Decrease and Invalidate

noun

• A change downward.
  • usage: "there was a decrease in his temperature as the fever subsided"; "there was a sharp drop-off in sales"
  • synonyms: lessening, drop-off
• A process of becoming smaller or shorter.
  • synonyms: decrement
• The amount by which something decreases.
  • synonyms: decrement
• The act of decreasing or reducing something.
  • synonyms: diminution, reduction, step-down

verb

• Decrease in size, extent, or range.
  • usage: "The amount of homework decreased towards the end of the semester"; "The cabin pressure fell dramatically"; "her weight fell to under a hundred pounds"; "his voice fell to a whisper"
  • synonyms: diminish, lessen, fall
• Make smaller.
  • usage: "He decreased his staff"
  • synonyms: lessen, minify

• (v.t.) To cause to grow less; to diminish gradually; as, extravagance decreases one's means.
• (v.) A becoming less; gradual diminution; decay; as, a decrease of revenue or of strength.
• (n.) To grow less, -- opposed to increase; to be diminished gradually, in size, degree, number, duration, etc. or in strength, quality or excellence; as, they days decrease in length from June to December.
• (v.) The wane of the moon.

verb

• Declare invalid.
  • usage: "The contract was annulled"; "void a plea"
  • synonyms: annul, quash, void, avoid, nullify
• Make invalid for use.
  • usage: "cancel cheques or tickets"
  • synonyms: cancel
• Show to be invalid.
  • synonyms: nullify
• Take away the legal force of or render ineffective.
  • usage: "invalidate a contract"
  • synonyms: void, vitiate

(v.t.) To render invalid; to weaken or lessen the force of; to destroy the authority of; to render of no force or effect; to overthrow; as, to invalidate an agreement or argument.