sit in on
Definition of sit in on
: to attend (something, such as a class or meeting) without officially participating She's been asked to sit in on the meetings.
Word by Word Definitions
: to rest on the buttocks or haunches
: perch, roost
: to occupy a place as a member of an official body
: the manner in which a garment fits
: an act or period of sitting
Seen and Heard
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