A phrase used to describe complete lack of interest in what another person is saying, considered rude or necessary, depending on the conversation.
Alternatively, this can be used as a defensive phrase, see examples, to attempt to save one's self from ridicule.
As a third option, it is also used as a peacemaking, forgiving phrase.

the thing that you don’t have when you’re phones percentage is over 20

showing an air of indifference; nonchalant; devil-may-care.

a phrase used by mentally retarded people, after every sentence they say.

Gangsta slang for "what's up"?

A word Jaden always USED to say..