leftfield vs piece of ground

leftfield and piece of ground both are nouns.

Word	Noun	Adjective	Verb	Adverb
leftfield	Yes	No	No	No
piece of ground	Yes	No	No	No

As nouns, piece of ground is a hypernym of leftfield; that is, piece of ground is a word with a broader meaning than leftfield:

Other hypernyms of leftfield include parcel, parcel of land, piece of land, tract.

leftfield (noun)	piece of ground (noun)
the fielding position of the player on a baseball team who is expected to field balls in the left third of the outfield (looking from home plate)	an extended area of land
the piece of ground in the outfield on the catcher's left