det·ri·ment / ˈdetrəmənt/ • n. the state of being harmed or damaged: he is engrossed in his work to the detriment of his married life. ∎  a cause of harm or damage: such tests are a detriment to good education.

DETRIMENT

Any loss or harm to a person or property; relinquishment of a legal right, benefit, or something of value.

Detriment is most frequently applied to contract formation, since it is an essential element of consideration, which is a prerequisite of a legally enforceable contract. To incur detriment means to cement a promise by either refraining from doing something that one has a legal right to do or by doing something that one is not under any legal obligation to do.

detriment XV. — (O)F. détriment or L. dētrīmentum, f. pt. stem dētrī- of dēterere wear away, f. DE- 2 + terere rub; see -MENT.
Hence detrimental XVII.