9-Letter Words Starting O & Ending S

• a tranquilizing drug (trade name Serax) used to treat anxiety and insomnia and alcohol withdrawal

• a substance that oxidizes another substance

• Either of two species of passerine bird in the genus Buphagus, in the monotypic family Buphagidae, endemic to sub-Saharan African savannah.

• a drug that induces labor by stimulating contractions of the muscles of the uterus

• make optimal; get the most out of; use best

• modify to achieve maximum efficiency in storage capacity or time or cost

• act as an optimist and take a sunny view of the world

• Clangula hyemalis, the long-tailed duck, a medium-sized seaduck.