|hard and fast|
|(hard-and-fast when prenominal) (esp of rules) invariable or strict|
hard and fast
Defined, fixed, invariable, as in We have hard and fast rules for this procedure. This term originally was applied to a vessel that has come out of water, either by running aground or being put in dry dock, and is therefore unable to move. By the mid-1800s it was being used figuratively.