Obsidional, ob-sid′i-ō-nal, adj. pertaining to a siege.—Also Obsid′ionary.
Obsignate, ob-sig′nāt, v.t. to seal, confirm.—n. Obsignā′tion.
Obsolescent, ob-so-les′ent, adj. going out of use.—n. Obsolesc′ence.—adj. Ob′solete, gone out of use: antiquated: (zool.) obscure: not clearly marked or developed: rudimental.—adv. Ob′soletely.—ns. Ob′soleteness; Obsolē′tion (rare); Ob′soletism. [L. obsolescens, -entis, pr.p. of obsolescĕre, obsoletum—ob, before, solēre, to be wont.]
Obstacle, ob′sta-kl, n. anything that stands in the way of or hinders progress: obstruction.—Obstacle race, a race in which obstacles have to be surmounted or circumvented. [Fr.,—L. obstaculum—ob, in the way of, stāre, to stand.]
Obstetric, -al, ob-stet′rik, -al, adj. pertaining to midwifery.—ns. Obstetric′ian, one skilled in obstetrics; Obstet′rics, the science of midwifery, or the delivery of women in childbed; Obstet′rix, a midwife. [L. obstetricius—obstetrix, -icis, a midwife—ob, before, stāre, to stand.]
Obstinate, ob′sti-nāt, adj. blindly or excessively firm: unyielding: stubborn: not easily subdued or remedied.—ns. Ob′stinacy, Ob′stinateness, the condition of being obstinate: excess of firmness: stubbornness: fixedness that yields with difficulty, as a disease.—adv. Ob′stinately. [L. obstināre, -ātum—ob, in the way of, stāre, to stand.]
Obstipation, ob-sti-pā′shun, n. extreme costiveness.
Obstreperous, ob-strep′ėr-us, adj. making a loud noise: clamorous: noisy.—v.i. Obstrep′erāte (Sterne).—adv. Obstrep′erously.—n. Obstrep′erousness. [L. obstreperus—ob, before, strepĕre, to make a noise.]
Obstriction, ob-strik′shun, n. obligation. [L. obstringĕre, obstrictum, to bind up.]
Obstropulous, ob-strop′ū-lus, adj. a vulgar form of obstreperous.