What does "fair share" mean?

An equitable or reasonable portion, especially in regards to contributions towards a particular duty, or the dividends thereof.

Fair share

Common synonyms include: adequate portion, allocation, allotment, appropriate, contribution, equitable.

/fɛə ʃɛə/ noun

noun ·Rare ·Advanced level

Noun

1
An equitable or reasonable portion, especially in regards to contributions towards a particular duty, or the dividends thereof. uncountable
"As the company had no dedicated janitor, all employees were expected to do their fair share of cleaning up after lunch."
2
A significant amount, often implied to be excessive or inordinate; a great deal of something. idiomatic, uncountable
"He endured a fair share of criticism during his lifetime, but his works are now universally considered to be masterpieces."

"As the company had no dedicated janitor, all employees were expected to do their fair share of cleaning up after lunch."

First attested in the mid-1600s.