"a backwards somersault in the air," 1906; see back (adj.) + flip (n.).

also back formation, "word formed from an existing word, often by removal of a suffix or supposed suffix," by 1887, from back (adv.) + formation.

board game for two persons, 1640s, baggammon, the second element from Middle English gamen, ancestor of game (n.); the first element (see back (adv.)) apparently is because pieces sometimes are forced to go "back." Known 13c.-17c. as tables.

"the ground or situation to the rear of what is in front or most engaging of the attention," 1670s, from back (adj.) + ground (n.); the original use was theatrical; the word was applied to painting ("part of a picture representing what is furthest from the spectator") by 1752. The figurative sense is attested by 1854.

1690s, "having the hand turned backward;" see back (adv.) + hand (n.). By 1894 in reference to handwriting that flows at a back-slant. As a verb, by 1857. As a noun, in reference to tennis, 1890, short for backhand stroke or volley. The figurative adjectival sense of "indirect" is from c. 1800. Related: Backhanded; backhanding.

1765, "done with the hand turned backward," from backhand (q.v.). The figurative sense "oblique in meaning, indirect; ambivalent, sarcastic," is from 1777. Related: Backhandedly; backhandedness.

"excavating equipment consisting of a digging bucket on the end of an articulated arm, typically mounted on the back of a tractor," by 1928, from back (n. or adj.) + hoe (n.).

1590s, "support at the back;" 1640s, "retreat;" verbal noun from back (v.). The physical sense of "anything placed at or attached to the back of something else" is from 1793. The meaning "musical accompaniment" is recorded from 1937.

1815, of machinery, "reaction of wheels on each other produced by an inconstant load," from back (adj.) + lash (n.) "a blow, stroke." In the metaphoric sense, it is attested from 1929.

"without a back," 1919, in reference to women's gowns and dresses, earlier of benches, from back (n.) + -less.