From The Collaborative International Dictionary of English v.0.48 [gcide]:
Disallow \Dis`al*low"\, v. t. [imp. & p. p. Disallowed; p. pr.
& vb. n. Disallowing.] [Pref. dis- + allow: cf. OF.
desalouer, desloer, to blame, dissuade.]
To refuse to allow; to deny the force or validity of; to
disown and reject; as, the judge disallowed the executor's
charge.
[1913 Webster]
To whom coming, as unto a living stone, disallowed
indeed of men, but chosen of God. --1 Pet. ii.
4.
[1913 Webster]
That the edicts of C[ae]sar we may at all times
disallow, but the statutes of God for no reason we may
reject. --Milton.
[1913 Webster]
Note: This verb was sometimes followed by of; as, "What
follows, if we disallow of this?" --Shak. See Allow.
Syn: To disapprove; prohibit; censure; reject.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
disallow
v 1: command against; "I forbid you to call me late at night";
"Mother vetoed the trip to the chocolate store"; "Dad nixed
our plans" [syn: forbid, prohibit, interdict,
proscribe, veto, disallow, nix] [ant: allow,
countenance, let, permit]