topsy-turvy

The origin of the adverb and adjective are uncertain. Topsy is probably derived from top or tops, though this does not explain the -sy ending; it has been suggested that the latter comes from so (thus, top so) or from top-set or top-side, modified to match the -y ending of turvy. The term topside-turvy is mentioned in the Anglo-Irish writer Laurence Sterne’s novel, The Life and Opinions of Tristram Shandy, Gentleman (1759–1767).Turvy is probably derived from a rare (scarcely attested) obsolete English word terve, turve (“to be thrown down; to fall; to dash down; to cast, throw; to turn back or down; to fold or roll over”) + -y (suffix meaning ‘having the quality of; inclined to’), with turve inherited from Middle English terven (“to throw (something) down; to throw (something) into confusion; to level; to resort or turn (to something); to go, move; to turn; to collapse, fall”) […], perhaps from Old English *tierfan (compare Old English tearflian (“to roll over, wallow”)) or from Old English torfian (“to launch, throw; to shoot missiles at; to stone; to be tossed”), from Proto-Germanic *turbōną (“to fling, hurl”), *turbijaną (“to turn, twist”) (whence Old English ġetyrfian (“to assail with missiles; to assault, attack”)), from Proto-Indo-European *derbʰ- (“to spin, twist”). Thus, the term as a whole may literally mean “having the top side thrown or turned down”. The noun and verb are probably derived from the adverb and adjective.

来源：wiktionary