recognizance n.

early 15c., recognisen, "resume possession of land," a back-formation from recognizance, or else from Old French reconoiss-, present-participle stem of reconoistre "to know again, identify, recognize," from Latin recognoscere "acknowledge, recall to mind, know again; examine; certify," from re- "again" (see re-) + cognoscere "to get to know, recognize" (see cognizance).

With ending assimilated to verbs in -ise, -ize. The meaning "know (the object) again, recall or recover the knowledge of, perceive an identity with something formerly known or felt" is recorded from 1530s. Related: Recognized; recognizing.

"preliminary examination or survey," specifically "an examination of a territory or enemy position with a view to directing military operations," 1810, a word from the Napoleonic Wars, from French reconnaissance "act of surveying," literally "recognition," from Old French reconoissance "recognition, acknowledgement" (see recognizance).