trainband vs reserves

trainband and reserves both are nouns.

Word	Noun	Adjective	Verb	Adverb
trainband	Yes	No	No	No
reserves	Yes	No	No	No

As nouns, reserves is a hypernym of trainband; that is, reserves is a word with a broader meaning than trainband:

trainband: a company of militia in England or America from the 16th century to the 18th century
reserves: civilians trained as soldiers but not part of the regular army

Other hypernyms of trainband include company, militia.

trainband (noun)	reserves (noun)
a company of militia in England or America from the 16th century to the 18th century	civilians trained as soldiers but not part of the regular army