kettledrum n.

"metal vessel used for boiling or heating liquids over a flame," Old English cetil, citel (Mercian), from Proto-Germanic *katilaz (compare Old Saxon ketel, Old Frisian zetel, Middle Dutch ketel, Old High German kezzil, German Kessel), which usually is said to be derived from Latin catillus "deep pan or dish for cooking," a diminutive of catinus "deep vessel, bowl, dish, pot," from Proto-Italic *katino-.

This word has been connected with Greek forms such as [kotylē] "bowl, dish." Yet the Greek word is no perfect formal match, and words for types of vessels are very often loanwords. It seems best to assume this for catinus too. [de Vaan]

One of the few Latin loan-words in Proto-Germanic, along with *punda- "measure of weight or money" (see pound (n.1)) and a word relating to "merchant" that yielded cheap (adj.). "[I]t is striking that all have something to do with trade" [Don Ringe, "From Proto-Indo-European to Proto-Germanic," Oxford 2006]. Perhaps the Latin word was confused with a native Germanic one.

Spelling with a -k- (c. 1300) probably is from influence of Old Norse cognate ketill. The smaller sense of "tea-kettle" is attested by 1769.

Kettle of fish "complicated and bungled affair" (1715), sometimes is said to be from a Scottish custom of a kettle full of fish cooked al fresco at a boating party or picnic, but this custom is not attested by that phrase until 1790. Perhaps it is rather a variant of kittle/kiddle "weir or fence with nets set in rivers or along seacoasts for catching fish" (c. 1200, in the Magna Charta as Anglo-Latin kidellus), from Old French quidel, probably from Breton kidel "a net at the mouth of a stream."

Kettle was used in geology for "deep circular hollow in a river bed or other eroded area, pothole" (1866), hence kettle moraine (1883), one characterized by such features.

early 15c., drom, "percussive musical instrument consisting of a hollow wooden or metallic body and a tightly stretched head of membrane," probably from Middle Dutch tromme "drum," a common Germanic word (compare German Trommel, Danish tromme, Swedish trumma) and probably imitative of the sound of one.

Not common before 1570s; the slightly older, and more common at first, word was drumslade, apparently from Dutch or Low German trommelslag "drum-beat," "though it does not appear how this name of the action came to be applied to the instrument" [OED], and the English word might be a shortening of this. Other earlier words for it were tabour (c. 1300, ultimately from Persian; see tabor) and timpan (Old English; see tympanum).

In machinery, the word was applied to various contrivances resembling a drum from 1740. In anatomy, "the tympanum of the ear," 1610s. Meaning "receptacle having the form of a drum" is by 1812. Drum-major (1590s) originally was "chief or first drummer of a military regiment;" later "one who directs the evolutions of a marching corps."