To restrict (an activity etc.)
To supply with a ration; to limit (someone) to a specific allowance of something.
To portion out (especially during a shortage of supply); to limit access to.
A portion of some limited resource allocated to a person or group.
To keep in possession or use.
To employ by paying a retainer.
To hold back (a pupil) instead of allowing them to advance to the next class or year.
To keep in one's pay or service.
To hold secure.