A solemn promise, often invoking a divine witness, regarding one's future action or behavior.
ObfuscateTo deliberately make something unclear or difficult to understand.
OblivionThe state of being unaware or unconscious of what is happening around one.
ObliviousUnaware or uninformed about something.
OccultRelating to magical or supernatural beliefs, practices, or phenomena.
OfferTo present or propose something for acceptance.
OjukúA term in the Igbo language meaning 'the path to wealth' or 'road to prosperity'.
OmerA biblical measure of grain, specifically a sheaf.
OmitTo leave out or exclude, either intentionally or forgetfully.
OntologyThe branch of metaphysics dealing with the nature of being and existence.
OnyeA term meaning 'person' or 'one' in Igbo, a language spoken in Nigeria.
OperateTo perform a function or action.
OptTo make a choice or decision from a range of possibilities.
OpticalRelating to sight or the eye.
OptimalBest or most favorable; most desirable under the circumstances.
OptimismA hopeful outlook on life, believing that good things will happen.
OptimumThe most favorable or desirable condition or level.
OptionalAvailable to be chosen but not obligatory.
OrA conjunction used to link alternatives.
OracleA person or medium through whom advice or prophecy is sought from the gods.