ocarina
occasion, , on rare occasions 
occasional   , , 
occasionalism
occasionally,   , 
Occident,  
occidental,    ,  
occidentalism, ,   
occipital
occiput
occlude, , 
occlusion, , 
occult, , 
occulting light  
occultism
occupancy, ,  
occupant, , 
occupation, ,  
occupational, occupational hazards ,    
occupier, ,  
occupy, , 
occur, , to occur again 
occurrence, , an everyday occurrence  
ocean,  ,  
ocean-going
Oceanian  ,  ,   
oceanic, , = Oceanian
oceanography
ocelot
ochlocracy
ochre,  - , 
octa--
octagon
octagonal
octahedral
octahedron, 
octal, 
octane, , octane number  
octangular= octagonal
octant,   ,   45 
octarchy
octave, , 
octavo  1/8  
octennial,     
octet,    
octette,    
octillion   
October, , the Great October Socialist Revolution    
octodecimo  1/18  
octogenarian,  ,  
octonarian,  
octopus, 
octoroon, 
octosyllabic,  
octosyllable , = octosyllabic
octuple, 
ocular, , 
oculist
