Deferral, generally, refers to putting off something until a future date, such as the payment of taxes. For instance, deposits made to some IRA accounts are subject to tax deferral, where taxes are not paid on deposits made until they are withdrawn.
Deferral, in the labor law context, refers to a policy of the National Labor Relations Board (NLRB) not to process unfair labor practice charges if the charge can be filed as a grievance and taken up through a grievance and arbitration procedure. The NLRB reviews the resulting grievance settlement or arbitration decision. If it is "clearly repugnant" to the National Labor Relations Act, the NLRB issues a complaint.
