ONS is an acronym indicating the common dating phenomenon One Night Stand. You can use the acronym ONS to indicate a person with whom you have had said One Night Stand.

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.

ONS simply means one night stand.

Usually used by the male population.

This stands for "One-Night-Stand" and is used by some males to inform thier friends what they think of certain women in the club.