GRE

opalescent - iridescent

opaque - dark; not transparent

opiate - sleep producer; deadener of pain

opportune - timely; well chosen

opportunist - individual who sacrifices principles for expediency by taking advantage of circumstances

opprobrium - infamy; vilification

optician - maker and seller of eyeglasses

optimist - person who looks on the bright side

optimum - most favorable

optional - not compulsory; left to one's choice

227 228 229 230 231 232 233 234 235 236 237