تأكد

Verb

 * 1) to be confirmed, to prove to be true
 * 2) to be undeniable, to be urgent
 * 3) to be strengthened, to be fortified
 * 4) to be or become convinced or certain
 * 5) to ascertain

Usage notes
According to Lane, the more correct verb to use in place of this one is, with similar meanings.

Etymology
From.

Verb

 * 1)  to confirm, to make sure