Definition of underside:
derriere, rear end, buns, bum, prat, ass, hindquarters, butt, hind end, merchantman, root, rump, tail end, can, fundament, fanny, tooshie, buttocks, over, tail, rear, undersurface, bottomland, bottom of the inning, behind, seat, posterior, bed, bottom, freighter, arse, stern, keister, nates, merchant ship, tush, backside.
- "The Adventures of Bobby Orde", Stewart Edward White.
- "Tropic Days", E. J. Banfield.
- "Jack Haydon's Quest", John Finnemore.