Outstanding
Part of speech: adjective
Definition: prominent or noticeable; standing out from others distinguished from others by its superiority projecting outwards unresolved; not settled or finished owed as a debt
Example sentence: The origin of life is one of the great outstanding mysteries of science.
Salient
Part of speech: noun
Definition: an outwardly projecting part of a fortification, trench system, or line of defense
Part of speech: adjective
Definition: prominent, worthy of note; pertinent or relevantDepicted in a leaping posture.