asséner

To deal a heavy blow (asséner un coup) or, figuratively and very commonly, to state something forcefully, bluntly, or dogmatically (asséner une vérité, des certitudes) — often with a mildly critical connotation of talking down to someone.

• Le champion assena un coup fatal à son adversaire. — The champion dealt his opponent a fatal blow.
• Il assène ses certitudes sans jamais douter. — He states his convictions bluntly, never doubting.
• Elle lui asséna la vérité sans ménagement. — She hit him with the truth, no holds barred.

The figurative sense — bluntly asserting an opinion as if it were obvious fact — is at least as common as the literal 'deal a blow' sense, and usually carries a mildly critical tone about the speaker's certainty.

Often confused with assener.