Pointed Weapons

Word	Etymology
Javelin	A light spear thrown with the hand and used as a weapon. Middle English, from Old French javeline, diminutive of javelot, of Celtic origin
Spear	A weapon consisting of a long shaft with a sharply pointed end. Middle English spere, from Old English.
Lance	A thrusting weapon with a long wooden shaft and a sharp metal head. 12c., from O.Fr. lance, from L. lancea "light spear," possibly of Celtic origin.
Pike	A long spear formerly used by infantry. French pique, from Old French, from piquer, to prick, from Vulgar Latin piccare, ultimately of imitative origin.
Partisan	Staved weapon with a broad blade at the top and a cutting edge at both sides. Carried by captains and lieutenants as a badge of rank in the 17th century. Withdrawn in 1684. Yeoman of the Guard still carry Partisans.
Halberd	Wooden shafted weapon of 5 to 6 feet with a metal head having a broad cutting edge on one side and a hook on the other. Much used from 15th to 16th centuries. Carried by infantry sergeants until 1790.
Spontoon	A short pike carried by infantry officers up to 1775 and infantry sergeants between 1791 and 1830. French sponton, from Latin punctum, from neuter past participle of pungere, to pierce, prick.
Assegai	A light spear or lance, especially one with a short shaft and long blade for close combat, used by Bantu peoples of southern Africa. Obsolete French azagaie, probably from Old Spanish azagayah, from Arabic az-zagaya : al-, the + Berber zagaya, spear.
Bayonet	Short spear- spike- and knife-like weapons of varying lengths affixed to the muzzles of rifles and use in close combat. Original weapon thought to have been invented in Bayonne in the 17th century.

Edged Weapons

Word	Etymology
Sword	O.E. sweord, from P.Gmc. *swerdan, related to O.H.G. sweran "to hurt," from P.Germanic. swer- "to cut."
Saber	A heavy cavalry sword with a one-edged, slightly curved blade. French sabre, from obsolete German sabel, from Middle High German, from Hungarian száblya, from szabni, to cut.

Firearms

Word	Etymology
Gun	13c. gunne "an engine of war that throws rocks, arrows or other missiles," probably a shortening of woman's name Gunilda, found in M.E. gonnilde "cannon" and in an Anglo-L. reference to a specific gun from a 1330 munitions inventory of Windsor Castle ("...una magna balista de cornu quae Domina Gunilda ..."), from O.N. Gunnhildr, woman's name (from gunnr + hildr, both meaning "war, battle"). The identification of women with powerful weapons is common historically (cf. Big Bertha, Brown Bess, etc.); meaning shifted with technology, from cannons to firearms as they developed 15c.
Arquebus	Simple Matchlock gun, carrying a solid bullet in a cylindrical barrel. Accurate to about 50m. Weapons of this kind were in military use from 1486-1680.
Musket	A smoothbore shoulder gun used from the late 16th through the 18th century. French mousquet, from Italian moschetto, a type of crossbow, musket, from moschetta, little fly, bolt of a crossbow, diminutive of mosca, fly, from Latin musca. Hence Musketeer.
Flintlock	Technology dates from approx. 1640, although introduction into the Army was very slow and it wasn't until the "Brown Bess" flintlock weapon replaced earlier matchlock pieces.
Fusil	A light flintlock musket. French, steel in a flintlock, firearm, from Old French *fuisil, steel for a tinderbox, from Vulgar Latin focilis* (petra), fire-(stone), from Late Latin *focus*, fire, from Latin, hearth. Hence Fusilier, a soldier in any of certain British army regiments formerly armed with fusils.
Pistol	c.1570, from M.Fr. pistole "short firearm," from Ger. Pistole, from Czech pis'tala "firearm," originally "pipe," from pisteti "to whistle," of imitative origin, related to Rus. pischal "shepherd's pipe." Also borrowed from M.Fr. pistolet, possibly from It. pistolese, in reference to Pistoia, town in Tuscany noted for gunsmithing.
Carbine	A shortened rifle. 1590, from Fr. carabine, used of light horsemen and also of the weapon they carried, perhaps from O.Fr. escarrabin "corpse-bearer during the plague," lit. (probably) "carrion beetle," an epithet for archers from Flanders. A Carabinier (or Carabineer) was a mounted soldier equipped with a Carbine instead of a sword. Typically Carabiniers were converted from Dragoons.
Dragon	A heavy pistol. 1622, from Fr. dragon "carbine, musket," because the guns "breathed fire" like a dragon. A Dragoon was a mounted soldier equipped with a Dragon instead of a sword. These troops were mounted on relatively poor/cheap horses and were expected to dismount to fight (unlike cavalry who achieve their shock effect when mounted).
Rifle	1775, used earlier of the grooves themselves (1754), noun use of rifled (adj.), from verb meaning "to cut spiral grooves in" (a gun barrel), probably from Fr. rifler, from O.Fr. rifler "to scratch or groove".
Machine Gun (MG)	Weapon capable of rapid and sustained fire. First successful design demonstrated by Maxim in 1884. British weapons of this class include: Maxim, Vickers, Browning, Lewis, Hotchkiss, Vickers-Berthier, Bren, GPMG, LSW.
Sub-Machine Gun (SMG)	Hand-held automatic weapon firing small calibre rounds. Concept originated with German Bergmann Musquete (1916). British weapons of this class were: Thompson, Lanchester, Sten, De Lisle Carbine and Sterling.

Particular Firearms

Word	Etymology
Sten	Named for Shepherd-Turpin-Enfield. Developed in 1941 and made of mainly stamped metal parts. Thousands of Sten guns were air-dropped to partisans in occupied Europe. Replaced by the Sterling in 1953.
Sterling	Submachine gun developed in the 1940s by the Patchett at the Sterling Armament company, Dagenham, UK. The wepaon was adopted by British Army in 1953. It remained in army service well untill early 1990s, when it was replaced by L85A1 assault rifle.
Bren	Named for Brno/Enfield - as it was based on the Czech ZB26 design. British Light Machine Gun (LMG).
Gatling	An American machine gun, consisting of a cluster of barrels which, being revolved by a crank, are automatically loaded and fired. Named after inventor, R.J. Gatling.

If we're going all anoraky and into rivet counting mde, here's the real deal.

The Sten was developed by R.V. Shepperd and H.J. Turpin at Enfield , and it's name comes from the initial letters of their surnames and the first two of Enfield.
They were mainly produced by BSA, (at Shirley then Tysely,) and by the Royal Ordnance Factory at Fazakerley. Many were also made in Canada.

G.H. Lanchester designed the submachinegun which bore his name at the Sterling Engineering Company.
Toward the end of WWII G.W. Patchett developed a new sub also at Dagenham. The Patchett was first issued in 1951 then modified in 1953 as the L2A1. With other mods came the L2A2 then the L2A3, from which sprang the L34A1 supressed weapon. And a jolly fine toy that is too !

The earliest 5.56 weapon in British Army use was the M16, the same weapon as the USAF bought some while after. The M16A1 with it's forward assist was adopted later by the US Army and USMC.

Much of the terminology associated with Tanks is Naval

Turret
Sponson
Hull
Bow
Stern