- offerA proposal that has been made.
- oba halfpenny
- opposeTo attempt to stop the progression of; to resist or antagonize by physical means, or by arguments, etc.; to contend against.
- oblateA person dedicated to a life of religion or monasticism, especially a member of an order without religious vows or a lay member of a religious community.
- oblatumAn oblate spheroid; a figure described by the revolution of an ellipse about its minor axis.
- obluctationopposition; resistance
- os-Against; facing; a combining prefix found in verbs of Latin origin.