unroll v.

prefix of reversal, deprivation, or removal (as in unhand, undo, unbutton), Old English on-, un-, from Proto-Germanic *andi- (source also of Old Saxon ant-, Old Norse and-, Dutch ont-, Old High German ant-, German ent-, Gothic and- "against"), from PIE *anti "facing opposite, near, in front of, before, against" (from PIE root *ant- "front, forehead," with derivatives meaning "in front of, before").

More or less confused with un- (1) through similarity in the notions of "negation" and "reversal;" an adjective such as unlocked might represent "not locked" (un- (1)) or the past tense of unlock (un- (2)).

early 14c., rollen, "turn over and over, move by rotating" (intransitive); late 14c. in the transitive sense of "move (something) by turning it over and over;" from Old French roeller "roll, wheel round" (Modern French rouler), from Medieval Latin rotulare, from Latin rotula, diminutive of rota "wheel" (see rotary). Related: Rolled; rolling.

From c. 1400 as "wrap or cover by rolling or enclosing" in something, also "wrap round and round an axis;" early 15c. as "press or level with a roller." From 1510s as "to move or travel on wheels or by means of rolling." Of sounds (such as thunder) somehow suggestive of a rolling ball, 1590s; of a drum from 1680s.

Of spoken sounds, "to utter with vibrations of the tongue," by 1846. Of eyes, from late 14c. (rolle his eyne), originally suggestive of ferocity or madness. Of a movie camera, "to start filming," from 1938. Sense of "rob a stuporous drunk" is by 1873, from the action required to get to his pockets. To roll up "gather, congregate" is from 1861, originally Australian. To roll with the punches is a metaphor from boxing (1940). To roll them bones was old slang for "play at dice" (1929). Heads will roll is a Hitlerism:

If our movement is victorious there will be a revolutionary tribunal which will punish the crimes of November 1918. Then decapitated heads will roll in the sand. [1930]