"physically demanding" (of manual labor), 1849; see back (n.) + break (v.).

"a strong beat regularly falling on a normally unaccented beat of a bar," 1928, in jazz, from back (adj.) + beat (n.). Later also in popular music.

also pullback, 1660s, "act or action of pulling back," from the verbal phrase; see pull (v.) + back (adv.). From 1951 in the military sense of "orderly withdrawal of troops."

1610s, "to give and return mutually," a back-formation from reciprocation, or else from Latin reciprocatus, past participle of reciprocare "rise and fall, move back and forth; reverse the motion of," from reciprocus "returning the same way, alternating" (see reciprocal). Sense of "cause to move back and forth" is from 1650s; intransitive sense of "move backward and forward" is from 1670s. Meaning "to give or do in response, act in return or response" is from 1820. Related: Reciprocated; reciprocating.

"to move in waves," 1660s, back-formation from undulation. Related: undulated, undulating.

1520s, "a reflexive mode of expression;" 1560s, "act of making a return (especially if mutual), mutual giving and returning, interchange of acts," from Latin reciprocationem (nominative reciprocatio) "retrogression, alternation, ebb," noun of action from past-participle stem of reciprocare "move back, turn back," also "come and go, move back and forth;" from reciprocus "returning the same way; alternating" (see reciprocal).

"move backward; deteriorate," 1816, probably a back-formation from retrogression. Related: Retrogressed; retrogressing.

"move in a circle or spiral," 1763 (implied in gyrated), back-formation from gyration. Related: Gyrated; gyrating.

early 14c., remouven, remuvien, remēven, "take (something) away; dismiss" from an office, post or situation; from Old French removoir "move, stir; leave, depart; take away," from Latin removere "move back or away, take away, put out of view, subtract," from re- "back, away" (see re-) + movere "to move" (from PIE root *meue- "to push away").

Sense of "go away, leave, depart, move" from a position occupied is from late 14c.; the intransitive sense of "change (one's) place, move from one place to another" also is from 14c. Related: Removed; removing.

also back-pedal, 1883, in bicycling, move the pedals backward; see back (adv.) + pedal (v.). Formerly one of the ways to apply the brakes in a simple bicycle. Related: Backpedalling (1887).