PDFWAC 192-100-075
Domestic partner.
For purposes of this title:
(1) "Domestic partner" means:
(a) Two adults who have registered as a domestic partnership with the Washington secretary of state; or
(b) A legal union of two persons of the same sex that was formed in and is legal in any state or jurisdiction.
(2) "Domestic partner" does not include partnerships formed by individuals of the opposite sex except as provided by RCW 26.60.030 or the equivalent law of another state.