weakened vs decreased

weakened and decreased both are adjectives.

Word	Noun	Adjective	Verb	Adverb
weakened	No	Yes	No	No
decreased	No	Yes	No	No

weakened (adjective)	decreased (adjective)
damaged; used of inanimate objects or their value	made less in size or amount or degree
reduced in strength
mixed with water
impaired by diminution
made weak or weaker