osmesis, osmolality, osmosis, osmotic pressure, ossicle, ossification, osteocyte, osteogenesis, osteology, ostertagia, ostiole, ostrea, ostrich, otoacariasis, otomycosis, otter, ounce, outbreak, outbreeding, outburst, outcome, outcrop, outcrossing, outdoor, outer, outfall, outfit, outflanking, outflow, outgassing - English-Kazakh Ecological Dictionary - Казахские словари