Origin and history of lunk

Middle English hed, from Old English heafod "top of the body," also "upper end of a slope," also "chief person, leader, ruler; capital city," from Proto-Germanic *haubid (source also of Old Saxon hobid, Old Norse hofuð, Old Frisian haved, Middle Dutch hovet, Dutch hoofd, Old High German houbit, German Haupt, Gothic haubiþ "head"), from PIE root *kaput- "head."

Modern spelling is early 15c., representing what was then a long vowel (as in heat) and remained after pronunciation shifted. Of rounded tops of plants from late 14c. The meaning "origin of a river" is mid-14c. The meaning "obverse of a coin" (the side with the portrait) is from 1680s; meaning "foam on a mug of beer" is attested by 1540s; meaning "toilet" is from 1748, based on location of crew toilet in the bow (or head) of a ship.

Synecdochic use for "person" (as in head count) is attested by late 13c.; of cattle, etc., in this sense from 1510s. As a height measure of persons, from c. 1300. Meaning "drug addict" (usually in a compound with the preferred drug as the first element) is from 1911.

To be over (one's) head "beyond one's comprehension" is by 1620s. To give head "perform fellatio" is from 1950s. Phrase heads will roll "people will be punished" (1930) translates Adolf Hitler. Head case "eccentric or insane person" is from 1966. Head game "mental manipulation" attested by 1972. To put heads together "consult" is from late 14c.

early 14c., lumpe, "small mass of material, solid but of irregular shape" (1224 as surname), etymology and original sense unknown. Perhaps it was in Old English, but it is not recorded there. Perhaps from a Scandinavian or continental source: Compare Danish lumpe "block, stump, log" (16c.), Middle High German lumpe, early modern Dutch lompe. All appear in the Middle Ages; there seems to be no trace of the word in older Germanic languages.

Late 15c. as "protuberant part;" from 1520s as "a great quantity;" 1590s as "dull, stupid person." Phrase lump in (one's) throat "swelling in the throat," especially "feeling of tightness brought on by emotion," is from 1803. Lumps "hard knocks, a beating" is colloquial, from 1934. Lump sum, covering a number of items at one time, is from 1867 (the same sense of lump is in lump-work, 1851).