(1):

(v. t.) To make thinner or more liquid by admixture with something; to thin and dissolve by mixing.

(2):

(v. t.) To diminish the strength, flavor, color, etc., of, by mixing; to reduce, especially by the addition of water; to temper; to attenuate; to weaken.

(3):

(v. i.) To become attenuated, thin, or weak; as, it dilutes easily.

(4):

(a.) Diluted; thin; weak.