grass parakeet vs Melopsittacus undulatus

grass parakeet and Melopsittacus undulatus both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass parakeet	Yes	No	No	No
Melopsittacus undulatus	Yes	No	No	No

As nouns, grass parakeet and Melopsittacus undulatus are synonyms defined as:

grass parakeet and Melopsittacus undulatus: small Australian parakeet usually light green with black and yellow markings in the wild but bred in many colors

Other synonyms of grass parakeet include budgereegah, budgerigar, budgerygah, budgie, lovebird, shell parakeet.

grass parakeet (noun)	Melopsittacus undulatus (noun)
small Australian parakeet usually light green with black and yellow markings in the wild but bred in many colors	small Australian parakeet usually light green with black and yellow markings in the wild but bred in many colors