The answer is a single noun.
Built from parts:
- (morphs into boast or seize) + (BIV BUTY)
As a whole:
- could be young
- could be treasure
- could be field bound
It could be simpler than it sounds.
I believe the answer is
GARBAGE
Built from parts:
(morphs into boast or seize) means
GARB, which could be anagram("morph") to BRAG("boast") and GRAB("seize").
(BIV BUTY) means
AGE, since IV means 4 in Roman, it can be read as "(AGE) BEFORE BEAUTY".
As a whole:
It could be young
A synonym for garbage is LITTER. A "litter" also refers to the young born to an animal (e.g., a litter of puppies).
could be treasure
the common idiom: "One man's garbage is another man's treasure."
could be field bound
may refers to landfill(a site for the garbage)?