yardman vs labourer

yardman and labourer both are nouns.

Word	Noun	Adjective	Verb	Adverb
yardman	Yes	No	No	No
labourer	Yes	No	No	No

As nouns, labourer is a hypernym of yardman; that is, labourer is a word with a broader meaning than yardman:

yardman: a laborer hired to do outdoor work (such as mowing lawns)
labourer: someone who works with their hands; someone engaged in manual labor

Other hypernyms of yardman include jack, laborer, manual laborer.

yardman (noun)	labourer (noun)
a laborer hired to do outdoor work (such as mowing lawns)	someone who works with their hands; someone engaged in manual labor
worker in a railway yard