Real Dictionary

restrain
verb: If you restrain an emotion or you restrain yourself from doing something, you prevent yourself from showing that emotion or doing what you wanted or intended to do.
verb: If you restrain someone, you stop them from doing what they intended or wanted to do, usually by using your physical strength.
verb: To restrain something that is growing or increasing means to prevent it from getting too large.

restrain in American English
to hold back from action; check; suppress; curb
transitive verb: to hold back from action; keep in check or under control; repress

restrain in British English
to hold (someone) back from some action, esp by force