omit
A word meaning to leave out which begins with an "o" is omit.
odd
it means something lol
Outset Origin
ovine
One Dutch word beginning with the letter "o" is "onmiddellijk," which means "immediately" in English.
Further Leave to Remain Other
The word is cease.
expelled
oleo
Ovine (refers to sheep).
A herb beginning with the letter "o" is oregano.