sit for

verb3

1. •
   To serve as a model for an artist or as the subject of a piece of art.

   • He sat for painters. — 1927
2. •
   To take care of children in the absence of their parents; to work as a babysitter for someone.
3. •
   To represent a political party in a place, especially the House of Lords.

   • Previously a crossbench peer in the House of Lords, now he sits for Labour. — 2025