Selectional restrictions

Selectional restrictions are the semantic restrictions that a word imposes on the environment in which it occurs.

Example
a verb like eat requires that its subject refers to an animate entity and its object to something concrete. A violation of the selectional restrictions of a word results in anomaly : in the mountain eats sincerity both restrictions are violated, rendering the sentence anomalous. The question whether selectional restrictions should be treated in syntax or semantics, or even outside grammar, as a matter of knowledge of the world, has been a point of debate.

Links
Utrecht Lexicon of Linguistics