leftover vs odd

leftover is a noun but odd is not a noun.

Word	Noun	Adjective	Verb	Adverb
leftover	Yes	Yes	No	No
odd	No	Yes	No	No

As adjectives, leftover and odd are synonyms defined as:

Other synonyms of leftover include left, left over, remaining, unexpended.

leftover (noun)	odd (noun)
a small part or portion that remains after the main part no longer exists

leftover (adjective)	odd (adjective)
not used up	not divisible by two
	an indefinite quantity more than that specified
	of the remaining member of a pair
	beyond or deviating from the usual or expected
	not used up
	not easily explained