olemus
sõltub kontekstist

näiteid
Wiktionary:
6. (linguistics, semantics) semantic widening, broadening of meaning
11. (telecommunications) a numerical code used to specify a specific telephone in a telecommunication network
12. (computing) a file extension
Files with the .txt extension usually contain text.
13. (computing) an optional software component that adds functionality to an application
a browser extension
14. (logic) the set of tuples of values that, used as arguments, satisfy the predicate

UML:
a use case extending the behavior of another use case