Restrain, curb, check, bridle, inhibit are comparable when they mean to hold a person or thing back from doing something or from going too far in doing something.
Restrain, the most comprehensive of these terms, may imply the intent either to prevent entirely or to keep under control or within bounds, but it usually suggests the operation of some force, authority, or motive that is sufficiently strong or compelling as to achieve the desired end.
Curb can imply either a sharp, drastic method of bringing under control or a guiding or controlling influence that tends to restrain or moderate something or to restrict a person’s freedom of action.
Check (see also ARREST 1 ) often implies the use of a method suggestive of a checkrein which holds up a horse’s head and prevents him from getting the bit between his teeth, but it may carry implications derived from other senses of the noun such as those of delaying or impeding motion or progress or of attacking or defeating some force or influence.
Bridle (see also STRUT ) carries a strong implication of bringing or keeping under one’s control (as by subduing, moderating, or holding in); it is used chiefly in respect to strong or vehement emotions or desires.
Inhibit (see also FORBID ) is a synonym of these terms in a predominantly psychological sense in which it implies the repression or suppression of certain emotions, desires, or thoughts by a curbing influence (as one’s conscience or religious principles or the social conventions of one’s class).