bunny

From bun (“rabbit”) +‎ -y (diminutive suffix). Probably from Scottish Gaelic bun (“bottom, butt, stump, stub”), from Old Irish bun (“the thick end of anything, base, butt, foot”), from Proto-Celtic *bonus, though its origin is uncertain. Compare also English bum. Together with rabbit, bunny has largely displaced its former rhyme cony (see cony for more).

From Middle English bony, boni (“swelling, tumor”), from Old French bugne, buigne (“swelling, lump”), from Old Frankish *bungjo (“swelling, bump”), from Proto-Germanic *bungô, *bunkô (“lump, clump, heap, crowd”). More at bunion, bunch

From Middle English bune (“hollow stalk or stem, drinking straw”), from Old English bune (“cup, beaker, drinking vessel; reed, cane”), of unknown origin. Related to English bun, boon (“the stalk of flax or hemp less the fibre”), Scots bune, boon, been, see bun, boon. Compare also bunweed

From bun (“small bread roll”) +‎ -y.