A covenant waiver is a shorter name for a loan covenant waiver: a written agreement by lenders not to exercise the rights they would otherwise have after a borrower fails, or expects to fail, to comply with a covenant. The main entry explains how waivers are requested, approved and documented.
The shorter term is used more broadly than the loan market alone. It also covers bonds and private placements, where a waiver is obtained from investors through a consent solicitation or a bondholder meeting organised with the bond trustee, rather than through a facility agent. In either market a waiver applies only to the breach and period it names. It does not change the covenant for the future, which requires an amendment, and it is distinct from forbearance, where the default remains in place but lenders agree to hold off enforcement.
A waiver is one of several possible outcomes of a covenant breach. Lenders commonly charge a fee and may ask for tighter terms, extra information or additional security in return.