Merriam-Webster's Dictionary and Thesaurus - Merriam-Webster [954]
1 : to be found or met with : APPEAR
2 : to come into existence : HAPPEN
3 : to come to mind Synonyms be, befall, betide, chance, come, go, happen, pass, transpire—more at HAPPEN oc·cur·rence noun 1 : something that takes place 2 : the action or process of occurring Synonyms affair, circumstance, episode, event, happening, incident, occasion, thing—more at EVENT ocean noun 1 : the whole body of salt water that covers nearly three fourths of the surface of the earth 2 : any of the large bodies of water into which the great ocean is divided Synonyms blue, brine, deep, sea; also high seas, main, waters; basin; Davy Jones's locker oce·an·ic adjective : of or relating to the ocean Synonyms marine, maritime, pelagic—more at MARINE ocean·ar·i·um noun, plural -iums or -ia : a large marine aquarium ocean·front noun : a shore area on the ocean ocean·go·ing adjective : of, relating to, or suitable for travel on the ocean ocean·og·ra·phy noun : a science dealing with the ocean and its phenomena — ocean·og·ra·pher noun — ocean·o·graph·ic adjective oce·lot noun : a medium-sized American wildcat ranging southward from Texas to northern Argentina and having a tawny yellow or gray coat with black markings ocher or ochre noun : an earthy usu. red or yellow iron ore used as a pigment; also : the color esp. of yellow ocher o'·clock adverb : according to the clock OCR abbreviation optical character reader; optical character recognition OCS abbreviation officer candidate school oct abbreviation octavo Oct abbreviation October oc·ta·gon noun : a polygon of eight angles and eight sides — oc·tag·o·nal adjective oc·tane noun : OCTANE NUMBER octane number noun : a number used to measure the antiknock properties of gasoline that increases as the likelihood of knocking decreases oc·tave noun 1 : a musical interval embracing eight degrees; also : a tone or note at this interval or the whole series of notes, tones, or keys within this interval 2 : a group of eight oc·ta·vo noun, plural -vos 1 : the size of a piece of paper cut eight from a sheet 2 : a book printed on octavo pages oc·tet noun 1 : a musical composition for eight voices or eight instruments; also : the performers of such a composition 2 : a group or set of eight Oc·to·ber noun [ORIGIN: ME Octobre, fr. OE October, fr. L, eighth month of the early Roman calendar, fr. octo eight] : the 10th month of the year oc·to·ge·nar·i·an noun : a person whose age is in the eighties oc·to·pus noun, plural -pus·es or -pi : any of various sea mollusks with eight long muscular arms furnished with suckers oc·to·syl·lab·ic adjective : composed of verses having eight syllables — octosyllabic noun 1ocular adjective 1 : based on what has been seen : VISUAL 2 : of or relating to the eye or the eyesight Synonyms optical, visual—more at VISUAL 2ocular noun : EYEPIECE oc·u·list noun 1 : OPHTHALMOLOGIST 2 : OPTOMETRIST 1OD noun : an overdose of a drug and esp. a narcotic 2OD verb OD'd or ODed; OD'·ing; OD's : to become ill or die from an OD 3OD abbreviation 1 doctor of optometry 2 [ORIGIN L oculus dexter] right eye 3 officer of the day 4 olive drab 5 overdraft 6 overdrawn odd adjective [ORIGIN: ME odde, fr. ON oddi point of land, triangle, odd number] 1 : being only one of a pair or set 2 : somewhat more than the number mentioned 3 : being an integer (as 1, 3, or 5) not divisible by two without leaving a remainder 4 : additional to what is usual <~ jobs> 5 : differing markedly from the usual or ordinary or accepted : STRANGE — odd·ness noun Synonyms bizarre, curious, far-out, funny, kinky, outlandish, outré, peculiar, quaint, queer, quirky, remarkable, screwy, strange, wacky, weird, wild; also aberrant, abnormal, atypical, extraordinary, fantastic, flaky, freak, freakish, idiosyncratic, phenomenal, singular, unique, unusual, unwonted;