necessarypiece
nounUK /ˈnɛsəsəri piːs/
US /ˈnɛsəˌsɛri piːs/
A necessary piece is a part that you must have to make something work or be complete.
The wheel is a necessary piece of the bicycle.
RELATED WORDS
OTHER MEANINGS
2. A key part of a plan or puzzle that cannot be left out.
That final clue was the necessary piece to solve the mystery.
3. A spare part you keep because you will need it later.
He packed a necessary piece for the broken machine.
4. Something small but very important in a set.
The battery is a necessary piece of the toy.