about to

(idiomatic, with infinitive verb) Indicates something that will happen very soon; indicates action that is imminent.

(as negative 'not about to', informal, originally US, Canada) Indicates that one has no intention of doing the stated thing at any time in the future.

(obsolete in affirmative) Indicates that one is preparing or planning to do the stated thing at some time in the future, not necessarily imminently.