tilled land vs ploughland

tilled land and ploughland both are nouns.

Word	Noun	Adjective	Verb	Adverb
tilled land	Yes	No	No	No
ploughland	Yes	No	No	No

As nouns, tilled land and ploughland are synonyms defined as:

tilled land and ploughland: arable land that is worked by plowing and sowing and raising crops

Other synonyms of tilled land include cultivated land, farmland, plowland, tillage, tilth.

tilled land (noun)	ploughland (noun)
arable land that is worked by plowing and sowing and raising crops	arable land that is worked by plowing and sowing and raising crops