Bottom
Old English botm, of Germanic origin; related to Dutch bodem ‘bottom, ground’ and German Boden ‘ground, earth’.
wiktionary
From Middle English botme, botom, from Old English botm, bodan(“bottom, foundation; ground, abyss”), from Proto-Germanic *butmaz, *budmaz, from Proto-Indo-European *bʰudʰmḗn(“bottom”). Cognate with Dutch bodem, German Boden, Icelandic botn, Danish bund; also Irish bonn(“sole (of foot)”), Ancient Greek πυθμήν(puthmḗn, “bottom of a cup or jar”), Sanskrit बुध्न(budhna, “bottom”), Persian بن (bon, “bottom”), Latin fundus(“bottom”) (whence fund, via French). The sense “posterior of a person” is from 1794; the “verb to reach the bottom of” is from 1808. bottom dollar(“the last dollar one has”) is from 1882.
etymonline
bottom (n.)
Old English botm, bodan "ground, soil, foundation, lowest or deepest part of anything," from Proto-Germanic *buthm- (source also of Old Frisian boden "soil," Old Norse botn, Dutch bodem, Old High German bodam, German Boden "ground, earth, soil"). This is perhaps from PIE root *bhudhno- "bottom" (source also of Sanskrit budhnah, Avestan buna- "bottom," Greek pythmen "foundation," Latin fundus "bottom, piece of land, farm," Old Irish bond "sole of the foot").
Meaning "fundamental character, essence" is from 1570s; to get to the bottom of some matter is from 1773. Meaning "posterior of a person" (the sitting part) is from 1794. Bottoms up as a call to finish one's drink is from 1875. Bottom dollar "the last dollar one has" is from 1857. To do or feel something from the bottom of (one's) heart is from 1540s. Bottom-feeder, originally of fishes, is from 1866.
bottom (v.)
1540s, "to put a bottom on," from bottom (n.). Meaning "to reach the bottom of" is from 1808 (earlier figuratively, 1785). Related: Bottomed; bottoming.
