【Marriage】 , 【matrimony】 ,  【wedlock】 ,  【wedding】 ,  【nuptial】 ,  【espousal】  are comparable though not always synonymous because they all refer directly or indirectly to acts by which a man and woman become husband and wife or to the state of being husband and wife.

【Marriage】 is the common term; it may apply to the rite or ceremony, but it more often applies to the legal or spiritual relation which is entered upon or to the state of being married or to the institution as an abstraction.

In extended use the term is applicable to any similarly close and intimate union.

【Matrimony】  is in most contexts interchangeable with  【marriage】 , but it is the more appropriate term in religious and sometimes in legal use; in many Christian churches it designates one of the seven sacraments.

The term therefore may be chosen in place of  【marriage】 when a religious ceremony or sanction is implied. In general the term is more often applied to the relationship which exists between husband and wife than to the ceremony or the state of 【marriage】 .

【Wedlock】 , chiefly legal or archaic, applies especially to 【marriage】 as a legally or ecclesiastically sanctioned relationship or state; thus, children born out of  【wedlock】 are children of parents who are not legally married.

【Wedding】 is the common term for the ceremony that marks a 【marriage】 and the festivities that accompany it.

【Nuptial】 , usually as the plural nuptials, is a more rhetorical term than  【wedding】 ; it also carries a stronger implication of an elaborate ceremony.

【Espousal】 , often as the plural espousals, differs little from  【nuptial】 except in its extended application. In the latter use it implies a spiritual union, especially one that is dependent upon a vow or pledge.