neighbourly vs neighborly

neighbourly and neighborly both are adjectives.

Word	Noun	Adjective	Verb	Adverb
neighbourly	No	Yes	No	No
neighborly	No	Yes	No	No

As adjectives, neighbourly and neighborly are synonyms defined as:

neighbourly and neighborly: exhibiting the qualities expected in a friendly neighbor

neighbourly (adjective)	neighborly (adjective)
exhibiting the qualities expected in a friendly neighbor	exhibiting the qualities expected in a friendly neighbor