"funeral rites," plural of obsequy.
late 15c., "prompt to serve, meekly compliant with the will or wishes of another, dutiful," from Latin obsequiosus "compliant, obedient," from obsequium "compliance, dutiful service," from obsequi "to accommodate oneself to the will of another," from ob "after" (see ob-) + sequi "to follow" (from PIE root *sekw- (1) "to follow"). Pejorative sense of "fawning, sycophantic, unduly compliant" had emerged by 1590s. Related: Obsequiously; obsequiousness (mid-15c.).
late 14c., obsequi, in plural, "funeral rites, a funeral," from Anglo-French obsequie, Old French obseque, osseque "funeral rites" and directly from Medieval Latin obsequiae, influenced in sense by confusion of Latin obsequium "compliance" (see obsequious) with exsequiae "funeral rites." Typically in plural, obsequies.
c. 1600, "that must be attended, followed, or kept," also "worthy of notice or mention," from Latin observabilis "remarkable, observable," from observare "watch over, note, heed, look to, attend to, guard, regard, comply with," from ob "in front of, before" (see ob-) + servare "to watch, keep safe," from PIE root *ser- (1) "to protect." From 1640s as "perceptible, capable of being observed." Related: Observably; observability.
mid-13c., observaunce, "act performed in accordance with prescribed usage," especially a religious or ceremonial one; late 14c., "care, concern, act of paying attention (to something)," from Old French observance, osservance "observance, discipline," and directly from Latin observantia "act of keeping customs, attention, respect, regard, reverence," from observantem (nominative observans), present participle of observare "watch over, note, heed, look to, attend to, guard, regard, comply with," from ob "in front of, before" (see ob-) + servare "to watch, keep safe," from PIE root *ser- (1) "to protect." Observance is the attending to and carrying out of a duty or rule. Observation is watching, noticing.
c. 1600, "attentive in perceiving or taking notice, characterized by good powers of observation," also "attentive in observing what is prescribed or required" (a law, custom, etc.), from observe + -ant, or else from French observant, past participle of observer (see observance). In reference to Judaism, "strict in acting in accordance with precepts," from 1902. As a noun from late 15c. Related: Observantly; observantness.
late 14c., observacioun, "the performance of a religious rite," from Old French observation (c. 1200) and directly from Latin observationem (nominative observatio) "a watching over, observance, investigation," noun of action from past-participle stem of observare "watch over, note, heed, look to, attend to, guard, regard, comply with," from ob "in front of, before" (see ob-) + servare "to watch, keep safe," from PIE root *ser- (1) "to protect." Sense of "act or fact of paying attention" is from 1550s. Meaning "a remark in reference to something observed" is recorded from 1590s.
1834, "of or pertaining to (scientific) observation," from observation + -al (1).
"building for observing astronomical phenomena," 1670s (in reference to Greenwich), from French observatoire, from observer (v.) "to observe, watch over, follow," from Latin observare "watch over," from ob "in front of, before" (see ob-) + servare "to watch, keep safe," from PIE root *ser- (1) "to protect."
