common law
Concise Oxford English Dictionary © 2008 Oxford University Press:
common law
▶noun
- 1 the part of English law that is derived from custom and judicial precedent rather than statutes.
■ the body of English law as adopted and adapted by the different states of the US.
- 2 [as modifier] denoting a partner in a marriage recognized in some jurisdictions (excluding the UK) as valid by common law, though not brought about by a civil or ecclesiastical ceremony.
■ denoting a partner in a relationship in which a man and woman cohabit for a period long enough to suggest stability.
'common law' also found in these Oxford entries:

