Missin; to be without someone who is fun to be with and great in bed, often refers to men named Andrew. Long bouts of "missin" can be associated with lonliness, boredom, excessive drinking and self pleasuring.
e.g. Yo I is missin ya Nigga
to do one, or to flex. a word used to let someone know you are going
im missin, i will catch you in a bit