Counsel, alert, advise, and caution are all synonyms for warn. Ignore and reassure are antonyms of warn. And here are 24 another word for warn.
Alert, apprise, forewarn, give a warning to, give fair warning to, give notice, inform, let someone know, make someone aware, notify, put someone on notice/guard, raise/sound the alarm, remind, tell, tip off, and put wise are all synonyms for warn.
Advise, caution, counsel, exhort, put on the alert, urge, and put someone on guard are all another word for warn.
Warn synonym page has a variety of synonyms that differ in length. 2 synonyms with 4, and 14 letters and 1 synonym with 5, 8, 10, 13, 16, 17, 18, and 23 letters. 6 synonyms with 6 letters and 3 synonyms with 7 letters. For a total of 21 another word for warn.
I need to warn you urgently.
They warn travelers about potential dangers.
She warned him not to proceed.
Please warn me if anything changes.