late 14c., from Old French anuller (13c.) or directly from Late Latin annullare "to make to nothing," from Latin ad- "to" (see ad-) + nullum, neuter of nullus "nothing" ( [..]

to make void, as to dissolve the bonds of marriage

an·nulled an·nul·ling 1 : to declare (a marriage) to have never validly existed compare divorce 2 a : to make legally void b : to declare to no longer have legal effect

(v) declare invalid(v) cancel officially

To end a marriage without the process of divorce. An annulment is typically only an option in the first few months of a valid marriage. See Nullity.    

To declare void in law. For example, when a marriage is annulled, the court says that it never was a marriage in law.

A divorced person who wishes to remarry in the Catholic Church can apply to a church court for an annulment or “declaration of nullity.” This means that the sacramental bond of matrimony never existed [..]