release (v.)
c.1300, "to withdraw, revoke (a decree, etc.), cancel, lift; remit," from Old French relaissier, relesser "to relinquish, quit, let go, leave behind, abandon, acquit," variant of relacher "release, relax," from Latin relaxare "loosen, stretch out" (see relax), source also of Spanish relajar, Italian relassare.

Meaning "alleviate, ease" is mid-14c., as is sense of "free from (duty, etc.); exonerate." From late 14c. as "grant remission, forgive; set free from imprisonment, military service, etc." Also "give up, relinquish, surrender." In law, c.1400, "to grant a release of property." Of press reports, attested from 1904; of motion pictures, from 1912; of music recordings, from 1962. As a euphemism for "to dismiss, fire from a job" it is attested in American English since 1904. Related: Released; releasing.
release (n.)
early 14c., "abatement of distress; means of deliverance," from Old French relais, reles (12c.), a back-formation from relesser, relaissier (see release (v.)). In law, mid-14c., "transferring of property or a right to another;" late 14c. as "release from an obligation; remission of a duty, tribute, etc." Meaning "act and manner of releasing" (a bow, etc.) is from 1871. Sense of "action of publication" is from 1907.