laborer vs labourer

laborer and labourer both are nouns.

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

As nouns, laborer and labourer are synonyms defined as:

laborer and labourer: someone who works with their hands; someone engaged in manual labor

Other synonyms of laborer include jack, manual laborer.

laborer (noun)	labourer (noun)
someone who works with their hands; someone engaged in manual labor	someone who works with their hands; someone engaged in manual labor