The noun custom (accepted practice or habit) has the related verb "to accustom."The adjective custom (special, made-to-order) has the related verb "to customize."
The word custom means "Accepted or habitual practice" We are by
our very nature people who accept customs readily, if they are in
accordance with the wishes of the rest of the people. England is an
example here, for it has no Constitution, but its laws are governed
by long standing custom that have stood the test of time.