flaw

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

• noun A quick, intense burst, especially of wind, rain, or snow.
• noun An imperfection, often concealed, that impairs soundness: synonym: blemish.
• noun A defect or shortcoming in something intangible.
• transitive verb To cause a flaw in; make defective.

from The Century Dictionary.

• To cause a flaw or defect in; break; crack; mar.
• To violate; invalidate.
• noun A flake; a fragment; a shiver.
• noun A thin cake, as of ice.
• noun A breach; a crack; a defect of continuity or cohesion; a weak spot or place.
• noun Any defect or imperfection; anything which impairs quality or character; a fault: as, a flaw in a will, a deed, or a statute.
• noun In weaving, a bore, tangle, or skip.
• noun A disease in which the skin recedes from the nails.
• noun A sudden gust of wind; a sudden and violent wind-storm.
• noun A sudden burst of noise and disorder; a tumult; an uproar.
• noun A sudden commotion of mind.
• noun Synonyms Gust, etc. See wind, n.
• An obsolete or dialectal variant of flay.

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

• transitive verb To crack; to make flaws in.
• transitive verb obsolete To break; to violate; to make of no effect.
• noun A crack or breach; a gap or fissure; a defect of continuity or cohesion.
• noun A defect; a fault
• noun obsolete A sudden burst of noise and disorder; a tumult; uproar; a quarrel.
• noun A sudden burst or gust of wind of short duration.

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

• noun A sudden burst or gust of wind of short duration.
• noun A storm of short duration.
• noun A sudden burst of noise and disorder; a tumult; uproar; a quarrel.
• noun A crack or breach, a gap or fissure; a defect of continuity or cohesion.
• noun A defect, fault, or imperfection, especially one that is hidden.
• noun A defect or error in a contract or other document which may make the document invalid.
• verb transitive To add a flaw to, to make imperfect or defective.
• verb intransitive To become imperfect or defective.

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

• noun an imperfection in an object or machine
• noun an imperfection in a plan or theory or legal document that causes it to fail or that reduces its effectiveness
• noun defect or weakness in a person's character
• verb add a flaw or blemish to; make imperfect or defective