'Decreased' definitions:

Definition of 'decreased'

adjective

Made less in size or amount or degree [syn: decreased, reduced] [ant: increased]

From: GCIDE

Decrease \De*crease"\, v. i. [imp. & p. p. Decreased; p. pr. & vb. n. Decreasing.] [OE. decrecen, fr. OF. decreistre, F. d['e]cro[^i]tre, or from the OF. noun (see Decrease, n.), fr. L. decrescere to grow less; de + crescere to grow. See Crescent, and cf. Increase.] 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. [1913 Webster]
He must increase, but I must decrease. --John iii. 30.
Syn: To Decrease, Diminish.
Usage: Things usually decrease or fall off by degrees, and from within, or through some cause which is imperceptible; as, the flood decreases; the cold decreases; their affection has decreased. Things commonly diminish by an influence from without, or one which is apparent; as, the army was diminished by disease; his property is diminishing through extravagance; their affection has diminished since their separation their separation. The turn of thought, however, is often such that these words may be interchanged. [1913 Webster]
The olive leaf, which certainly them told The flood decreased. --Drayton. [1913 Webster]
Crete's ample fields diminish to our eye; Before the Boreal blasts the vessels fly. --Pope. [1913 Webster]

From: GCIDE

decreased \decreased\ adj. made less in size or amount or degree. Opposite of increased. [Narrower terms: {attenuate, attenuated, faded, weakened}; belittled, diminished, small; cut, cut-rate; diminished, lessened; minimized; remittent; attenuated]
Syn: reduced. [WordNet 1.5]