pitch in phrasal verb informal ( see also ↑ pitch )
1 . to join others and help with an activity:
If we all pitch in, we’ll have it finished in no time.
pitch in with
Everyone pitched in with efforts to entertain the children.
2 . to join others and pay part of the money towards something:
They all pitched in and the money was collected within a few days.
3 . British English to start to eat hungrily:
Pitch in – there’s plenty.