(Greek: epieikes, reasonable)
An indulgent and benign interpretation of law, which regards a law as not applying in a particular case because of circumstances unforeseen by the lawmaker.
The lawmaker cannot foresee all possible cases that may come under the law, and it is therefore reasonably presumed that were the present circumstances known to the legislator he would permit the act, e.g., a mother presumes that she may miss Mass on Sunday when there is no one present to care for her baby.
Epikeia is not permitted, however, no matter how grave the inconvenience, if violation of the law would render an act null and void, e.g., to presume that marriage may be contracted because of grave inconvenience in spite of an existing diriment impediment.
New Catholic Dictionary