weaning vs substitution

weaning and substitution both are nouns.

Word	Noun	Adjective	Verb	Adverb
weaning	Yes	No	No	No
substitution	Yes	No	No	No

As nouns, substitution is a hypernym of weaning; that is, substitution is a word with a broader meaning than weaning:

weaning: the act of substituting other food for the mother's milk in the diet of a child or young mammal
substitution: the act of putting one thing or person in the place of another:

Other hypernyms of weaning include commutation, exchange.

weaning (noun)	substitution (noun)
the act of substituting other food for the mother's milk in the diet of a child or young mammal	the act of putting one thing or person in the place of another:
	an event in which one thing is substituted for another