assert Definition

assert
verb asserted, asserting

1. To state firmly.

Thesaurus: state, affirm, say, declare, aver, pronounce, proclaim, avow; Antonym: deny.
2. To insist on or defend (one's rights, opinions, etc).

Idiom: assert oneself

To state one's wishes, defend one's opinions, etc confidently and vigorously.

Etymology: 17c: from Latin asserere, from ad- to + serere to join.