"relating to knowledge," especially mystical or esoteric knowledge of spiritual things, 1650s, from Greek gnōstikos "knowing, good at knowing, able to discern," from gnōstos "known, perceived, understood," earlier gnōtos, from gignōskein "learn to know, come to know, perceive; discern, distinguish; observe, form a judgment," from PIE *gi-gno-sko-, reduplicated and suffixed form of root *gno- "to know."
late 14c., "careful observation of one's surroundings, attention to details and probable consequences" (with a view to choosing the safest course), from Old French circumspection (Modern French circonspection), from Latin circumspectionem (nominative circumspectio) "a looking around; foresight, caution," noun of action from past participle stem of circumspicere "to look around," from circum "around, round about" (see circum-) + specere "to look" (from PIE root *spek- "to observe").
1560s, from Kasper Schwenkfeld (1490-1561), Silesian Protestant mystic who founded the sect. Their original name for themselves was Confessors of the Glory of Christ. Schwenkfelder (n.) is attested from 1882.
They select their ministers by lot, maintain a strict church discipline, and do not observe the sacraments. They are now found chiefly in Pennsylvania. [Century Dictionary, 1890]
late 14c., "to fix the mind upon for careful examination, meditate upon," also "view attentively, scrutinize; not to be negligent of," from Old French considerer (13c.) "reflect on, consider, study," from Latin considerare "to look at closely, observe," probably literally "to observe the stars," from assimilated form of com "with, together" (see con-) + sidus (genitive sideris) "heavenly body, star, constellation" (see sidereal).
Perhaps a metaphor from navigation, but more likely reflecting Roman obsession with divination by astrology. Tucker doubts the connection with sidus, however, because it is "quite inapplicable to desiderare," and suggests derivation instead from the PIE root of English side meaning "stretch, extend," and a sense for the full word of "survey on all sides" or "dwell long upon."
From 1530s as "to regard in a particular light." Related: Considered; considering.
mid-14c., "devoted to (sacred) contemplation, devout," from Old French contemplatif (12c.) and directly from Latin contemplativus "speculative, theoretical," formed (after Greek theoretikos) from contemplat-, past-participle stem of contemplari "to gaze attentively, observe; consider, contemplate" (see contemplate). Meaning "given to continued and absorbed reflection" is from late 15c. Related: Contemplatively.
1925, from omphalo- + Greek -skepsis, from skeptesthai "to reflect, look, view" (from PIE root *spek- "to observe"). Also omphaloscopy (1931). Used earlier in the sense of "navel-gazer" were omphalopsychic (1892) and Omphalopsychite (1882) "one of a body of monks who believed the deep contemplation of the navel induced communion with God," a derisive name given to the Hesychasts.
"one who observes flights of birds for the purpose of taking omens," 1590s, from Latin auspex "interpreter of omens given by birds," from PIE *awi-spek- "observer of birds," from root *awi- "bird" + root *spek- "to observe." Compare Greek oionos "bird of prey," also "bird of omen, omen," and ornis "bird," which also could mean "omen."
"sharp-sighted," also "of acute mental discernment," 1630s, formed as an adjective to perspicacity, from Latin perspicax "sharp-sighted, having the power of seeing through; acute," from perspicere "look through, look closely at," from per "through" (from PIE root *per- (1) "forward," hence "through") + specere "look at" (from PIE root *spek- "to observe"). Related: Perspicaciously; perspicaciousness.