Equivalent to the phrase "I'm up for it," but abbreviated. It's similar to saying "I'm down." Meaning you're interested in joining in on the activity suggested in conversation.

A term used to reference cannabis/marijuana/weed.

Synonymous with "I'm awake." A two word phrase meaning that the speaker is, in fact, not asleep.

Awake; stimulated; conscious and responsive to external stimuli.

1. Some reference texts claim that “I'm up” is defined as physically out of bed. This is too specific to be precise. “Im up” (a colloquial shortening of “I'm up for it”) can also mean “Im down with it”. As spacial references, these definitions cannot coexist. Readers who deal with this inconsistency by choosing one definition and politicking for the exclusion of the other are invited to review the urban dictionary entry for “fuck off”.

2. For phrases meaning on one's feet, see: "up and about" or "up and at 'em".