- Used other than as an idiom: see look, up.
- We stayed up late to look up at the stars.
- (intransitive, idiomatic) To have better prospects, to improve.
- Things started looking up after Jim moved back in with his parents.
- (transitive, idiomatic) To obtain information about something from a text source.
- I didn't know what a mitochondrion was until I looked it up in a dictionary.
- (transitive) To track down or search for (someone) that one used to know.
used other than as an idiom
to have better prospects, to improve
to obtain information about something from a text source