nullity numb number numeracy numeral numerator numerical numerous nun nunnery nuptial nuptials nurse nursery nurture nut nut-brown nutmeg nutrient nutrition nutritionist nuts nutshell nutty nylon O-Bon oak OAP oar oarlock oarsman oarswoman oasis oath oatmeal oats obdurate OBE obedience obedient obese obesity obey obituary object objection objective objectivity objectless obligation obligatory oblige obliged oblique obliterate oblivion oblong obnoxious oboe oboist obscene obscenity obscure observance observation observe observer obsess obsession obsessive obsolete obstacle obstetric obstetrics obstinacy obstinate obstruct obstruction obtrusive obv obvious obviously obvs ocarina occasion occasional occasionally Occitan occult occupant occupation occupational occupationally occupied occupier occupy occurrence OCD ocean ocean-going