cancel

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To annul or invalidate.
• intransitive verb To decide or announce that (a planned or scheduled event) will not take place, especially with no intention of holding it at a later time.
• intransitive verb To cross out with lines or other markings. synonym: erase.
• intransitive verb To mark or perforate (a postage stamp or check, for example) to indicate that it may not be used again.
• intransitive verb To neutralize or equalize; offset.
• intransitive verb To remove (a common factor) from the numerator and denominator of a fractional expression.
• intransitive verb To remove (a common factor or term) from both sides of an equation or inequality.
• intransitive verb To neutralize one another; counterbalance.
• noun The act or an instance of canceling; a cancellation.

from The Century Dictionary.

• In printing, to mark on copy or proof (words or lines that are to be omitted).
• In bookbinding, to destroy (a leaf or section that is to be entirely suppressed).
• noun Latticework, or one of the cross-bars in latticework; a latticework or grated inclosure; hence, a barrier; a limit.
• noun [⟨ cancel, v.] In printing, a page, sheet, or other part of a printed work suppressed and destroyed before publication; the act of rejecting a part of a printed work.
• noun [⟨ cancel, v.] In music, the sign ♯, when used to nullify the effect of a sharp or a flat previously occurring either in the signature or as an accidental.
• To inclose with latticework or a railing.
• To draw lines across (something written) so as to deface; blot out or obliterate: as, to cancel several lines in a manuscript.
• To annul or destroy; make void; set aside: as, to cancel a debt or an engagement.
• In mathematics, to strike out or eliminate, as a number or quantity constituting a common factor in a dividend and divisor or the numerator and denominator of a fraction, or a common term in the two members of an equation.
• In printing, to strike out, reject, or throw aside, as some portion of a printed work.
• In music, to suspend the power of (a sharp or a flat) by inserting the sign ♯.
• Repeal, Rescind, etc. See abolish.
• To become obliterated or void.
• noun An order canceling or countermanding a previous order.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb obsolete To inclose or surround, as with a railing, or with latticework.
• intransitive verb obsolete To shut out, as with a railing or with latticework; to exclude.
• intransitive verb To cross and deface, as the lines of a writing, or as a word or figure; to mark out by a cross line; to blot out or obliterate.
• intransitive verb To annul or destroy; to revoke or recall.
• intransitive verb (Print.) To suppress or omit; to strike out, as matter in type.
• intransitive verb (Print) figures cast with a line across the face., as for use in arithmetics.
• noun obsolete An inclosure; a boundary; a limit.
• noun The suppression or striking out of matter in type, or of a printed page or pages.
• noun The part thus suppressed.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive To cross out something with lines etc.
• verb transitive To invalidate or annul something.
• verb transitive To mark something (such as a used postage stamp) so that it can't be reused.
• verb transitive To offset or equalize something.
• verb transitive (mathematics) To remove a common factor from both the numerator and denominator of a fraction, or from both sides of an equation.
• verb transitive (media) To stop production of a programme.
• noun A cancellation (US); (nonstandard in some kinds of English).
• noun obsolete An inclosure; a boundary; a limit.
• noun printing The suppression on striking out of matter in type, or of a printed page or pages.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb remove or make invisible
• verb postpone indefinitely or annul something that was scheduled
• noun a notation cancelling a previous sharp or flat
• verb make invalid for use
• verb make up for