NO, biggest is an adjective; the superlative form of big (big, bigger, biggest).
A Siberian Tiger is the biggest big cat
The adjective 'biggest' is the superlative form for the adjective 'big': big, bigger, biggest
big
The biggest "big" cat is the Siberian Tiger.
New Zealands biggest rock is a beach rock they can be as big as a big big super big mountin
Biggest - Big Star album - was created in 1994.
the world's biggest mythical creature is pretty big
BIG Asia is the biggest continent. It has 18.8 million square miles.
No, it is not. The word biggest is a superlative adjective meaning largest (most big). Although big is sometimes colloquially an adverb (made it big), this does not extend to bigger or biggest.
really big
BIG