(Latin: dispensatio, originally distribution or management)
A relaxation of the law in a particular case.
It is not an abrogation of the law nor an excuse from it but a release from its observance, granted by competent authority for good reasons.
The pope can dispense from all purely ecclesiastical laws no matter by whom they were passed; other authorities in the Church can dispense from the laws they themselves or their predecessors established.
From laws passed by a higher superior, only those can dispense who are granted the power either by provisions in the general law of the Church or by a special delegation.
Those who dispense from their own law can do so validly even without a proportionate cause, though they, too, usually demand one; but inferiors cannot validly dispense from law of their superiors except for a just reason.
As long as this reason continues, at least probably, the dispensation retains its force.
Dispensations are granted from fasting, abstinence, from vows in certain cases, reading the Divine Office, etc.
Dispensation, in matrimony, is the removal of an impediment by the Church.
New Catholic Dictionary