Definition of sit in on phrasal verb from the Oxford Advanced American Dictionary

 

sit in on

 phrasal verb
phrasal verb
 
jump to other results
Phrasal Verbs

sit in on something

 
jump to other results
to attend a meeting, class, etc. in order to listen to or learn from it rather than to take an active part I was allowed to sit in on an executive meeting.
See the Oxford Advanced Learner's Dictionary entry: sit in on