A gift by the husband to the wife in lieu nt her dower is recognised as:

Hiba is an unconditional gift under Islamic law. When a husband gives property to his wife in lieu of or as a substitute for her dower (mahr), it's a simple Hiba - a voluntary gift without consideration. Hiba-hil-iwaz involves exchange of gifts, and Hiba-ba-shartul-iwaz involves a gift with a condition that something be given in return, which don't apply here.