subside vs weaken

subside and weaken both are verbs.

Word	Noun	Adjective	Verb	Adverb
subside	No	No	Yes	No
weaken	No	No	Yes	No

As verbs, weaken is a hypernym of subside; that is, weaken is a word with a broader meaning than subside:

subside (verb)	weaken (verb)
wear off or die down	become weaker
sink down or precipitate	lessen the strength of
sink to a lower level or form a depression	reduce the level or intensity or size or scope of
descend into or as if into some soft substance or place	lessen in force or effect
	destroy property or hinder normal operations