openhanded openhandedness openhci openhearted openil opening opening line opening move opening night openly openmouthed openness openpmf openside plane openwork opepe opera opera bouffe Opera buffa opera cloak opera comique opera company opera glasses opera hat opera hood opera house opera singer opera star operable operagoer operand operant operant conditioning operas operate operate on operatic operatic star operating operating budget operating capability operating capital operating cost operating expense operating instructions operating microscope operating procedure operating room operating statement operating surgeon operating system operating table operating theater operating theatre operation operation code operation desert storm operational operational casualty operational cell operational damage operationalism operationalist operationally operations operations research operative operative field operatively operator operator gene operculate operculated operculum operetta operon operose operoseness opes Opheim Opheim, MT ophel opheodrys opheodrys aestivus opheodrys vernalis Ophibolus eximius Ophibolus triangulus ophidia ophidian ophidiidae ophidism Ophiobolus getulus Ophiocaryon paradoxum Ophiocephalus marulius ophiodon ophiodon elongatus ophiodontidae ophioglossaceae ophioglossales ophioglossum ophioglossum pendulum ophiolatry ophiophagus Ophiophagus bungarus ophiophagus hannah Ophiosaurus ventralis Ophioxylon serpentinum ophir Ophir, CO Ophir, UT ophisaurus ophiuchus ophiurida ophiuroidea ophni ophrah ophryon ophrys ophrys apifera Ophrys aranifera ophrys insectifera ophrys muscifera ophrys sphegodes ophthalmectomy ophthalmia ophthalmia neonatorum ophthalmic ophthalmic artery ophthalmic vein ophthalmitis ophthalmologist ophthalmology