It can be, in more than one usage.
A "negative charge" refers to electromagnetism.
A "negative value" is a mathematical use (less than zero).
A "negative report" is one that yields no affirmative or helpful result (absence).
A "negative review" is one that expresses faults (disapproval).
The noun uses of the word follow the same meanings, almost universally the opposite of the word "positive."
The negative adjective of "agreeable" is disagreeable.
The negative adjective for suitable is unsuitable.
The word unusual *is* an adjective, the negative of the adjective usual.A related adjective that has a different meaning is unused, the negative of the past participle used.
a negative adjective would be fat or chunky while a positive adjective meaning the same thing would be big build or heavy set.
yes
The adjective form of the noun queen is queenly. Related adjectives are queenlike and the negative adjective queenless.
despair
ineffective
No, it is not an adjective. The word "con" is a noun (a negative, or a convict) or a verb (to swindle).
No, it is not. Negative is an adjective related to a number. By itself, negative is not a number of any kind.
Here are the sentences: 'I am negative' or 'Today was a bad day for many negative reasons.'
Yes. Liquid is a noun and an adjective. (There is also a negative, illiquid, for some uses.)