Yea-great
Generally, a placating dodge employed by teens and young people who are not truly interested in committing to an action, event, project or celebration but lack the confidence, assertiveness just to say NO. Usually, this results in wasting other people's time in followup. It is used to avoid confrontation but ultimately to avoid discussion or justifying the reasons for not wanting to commit.
Samantha - Hey Susan how about heading out to this concert on next Sunday?
Susan - yea-great
Susan - yea-great