"that is no longer practiced or used, out of date, gone out of use, of a discarded type," 1570s, from Latin obsoletus "grown old, worn-out," past participle of obsolescere "fall into disuse, be forgotten about, become tarnished," which probably is from ob "away" (see ob-) + an expanded form of solere "to be used to, be accustomed" (see insolent).
"a hindrance, obstruction, impediment, or barrier; that which opposes or stands in the way," mid-14c., from Old French obstacle, ostacle "opposition, obstruction, hindrance" (13c.) and directly from Latin obstaculum "a hindrance, obstacle," with instrumental suffix *-tlom + obstare "stand before, stand opposite to, block, hinder, thwart," from ob "in front of, against" (see ob-) + stare "to stand," from PIE root *sta- "to stand, make or be firm."
The lover thinks more often of reaching his mistress than the husband of guarding his wife; the prisoner thinks more often of escaping than the gaoler of shutting his door; and so, whatever the obstacles may be, the lover and the prisoner ought to succeed. [Stendhal, "Charterhouse of Parma"]
Obstacle course "race course in which natural or artificial obstacles must be overcome" is attested by 1891.
"of or pertaining to a midwife or midwifery," 1742, from Modern Latin obstetricus "pertaining to a midwife," from obstetrix (genitive obstetricis) "midwife," literally "one who stands opposite (the woman giving birth)," from obstare "stand opposite to" (see obstacle). The true adjective would be obstetricic, "but only pedantry would take exception to obstetric at this stage of its career" [Fowler]. Related: Obstetrical.
"one skilled in obstetrics," 1793, from Latin obstetricia "midwifery" (from obstetricus; see obstetric) on model of physician.
late 14c., obstinacie, "hardness of heart, inflexibility of temper or purpose," from Medieval Latin obstinatia, from obstinatus "resolute, inflexible, stubborn" (see obstinate).
early 15c., obstinaunce, "non-compliance, self-willed persistence," from Medieval Latin obstinantia, from obstinatus "resolved, determined, resolute" (see obstinate). Earlier was obstinacioun "determination, resolution" (mid-14c.), from Old French.
"stubborn in adhering to one's own course, unyielding," late 14c., from Latin obstinatus "resolute, resolved, determined, inflexible, stubborn," past participle of obstinare "persist, stand stubbornly, set one's mind on," from ob "by" (see ob-) + stinare (related to stare "stand"), from PIE *ste-no-, from root *sta- "to stand, make or be firm." Related: Obstinately.
"action of blocking or stopping up," especially, in medicine, "constipation," 1590s, from Latin obstipationem (nominative obstipatio), noun of action from past-participle stem of *obstipare "action of blocking or stopping up," from ob "in front of; in the way of" (see ob-) + stipare "to press together, to pack" (see stiff (adj.)).
"clamorous, noisy, boisterous, especially in opposition," c. 1600, from Latin obstreperus "clamorous," from obstrepere "drown with noise, make a noise against, oppose noisily," from ob "against" (see ob-) + strepere "make a noise," from PIE *strep-, said to be imitative (compare Latin stertare "to snore," Old Norse þrefa "to quarrel," þrapt "chattering, gossip," Old English þræft "quarrel"). But de Vaan writes, "It is uncertain that *strep- goes back to PIE, since it is only found in Latin and Germanic." Extended sense of "resisting control, management, or advice" is by 1650s. Related: Obstreperously; obstreperousness.