oocyte
oocyte: n. an immature ovum in an ovary.

olympic
Olympic: adj. & n. --adj. of ancient Olympia or the Olympic games. --n. (the Olympics) the Olympic games. øOlympic game.
1 an ancient Greek festival held at Olympia every four years, with athletic, literary, and musical competitions.
2 a modern international revival of this as a sports festival held every four years since 1896 in different venues. [L Olympicus f. Gk Olumpikos of Olympus or Olympia (the latter being named from the games in honour of Zeus of Olympus)]

obliquity
oxhide
oxhide: n.
1 the hide of an ox.
2 leather made from this.

opera
obfuscate
obfuscate: v.tr.
1 obscure or confuse (a mind, topic, etc.).
2 stupefy, bewilder. øøobfuscation n. obfuscatory adj. [LL obfuscare (as OB-, fuscus dark)]

olecranon
olecranon: n. a bony prominence on the upper end of the ulna at the elbow. [Gk ole(no)kranon f. olene elbow + kranion head]

overman
overman: v. & n. --v.tr. (-manned, -manning) provide with too large a crew, staff, etc. --n. (pl. -men.
1 an overseer in a colliery.
2 Philos. = SUPERMAN.

occasion
occasion: n. & v. --n.
1 a a special or noteworthy event or happening (dressed for the occasion). b the time or occurrence of this (on the occasion of their marriage).
2 (often foll. by for, or to + infin.) a reason, ground, or justification (there is no occasion to be angry).
3 a juncture suitable for doing something; an opportunity.
4 an immediate but subordinate or incidental cause (the assassination was the occasion of the war). --v.tr.
1 be the occasion or cause of; bring about esp. incidentally.
2 (foll. by to + infin.) cause (a person or thing to do something). øon occasion now and then; when the need arises. rise to the occasion produce the necessary will, energy, ability, etc., in unusually demanding circumstances. take occasion (foll. by to + infin.) make use of the opportunity. [ME f. OF occasion or L occasio juncture, reason, f. occidere occas- go down (as OB-, cadere fall)]

oligocene
Oligocene: adj. & n. Geol. --adj. of or relating to the third epoch of the Tertiary period, with evidence of the first primates. °Cf. Appendix II. --n. this epoch or system. [as OLIGO- + Gk kainos new]

ombre
ombre: n. a card-game for three, popular in Europe in the 17th-18th c. [Sp. hombre man, with ref. to one player seeking to win the pool]

outfit
outfit: n. & v. --n.
1 a set of clothes worn or esp. designed to be worn together.
2 a complete set of equipment etc. for a specific purpose.
3 colloq. a group of people regarded as a unit, organization, etc.; a team. --v.tr. (also refl.) (-fitted, -fitting) provide with an outfit, esp. of clothes.