biggest

Of great size, large.

“Elephants are big animals, and they eat a lot.”

(of an industry or other field, often capitalized) Thought to have undue influence.

“Big Tech”

Popular.

“That style is very big right now in Europe, especially among teenagers.”

Adult.

“Kids should get help from big people if they want to use the kitchen.”

Fat.

“Gosh, she is big!”

Important or significant.

“What's so big about that? I do it all the time.”

(with on) Enthusiastic (about).

“I'm not big on the idea, but if you want to go ahead with it, I won't stop you.”

Mature, conscientious, principled; generous.

“I tried to be the bigger person and just let it go, but I couldn't help myself.”

Well-endowed, possessing large breasts in the case of a woman or a large penis in the case of a man.

“Whoa, Nadia has gotten pretty big since she hit puberty.”

(sometimes figurative) Large with young; pregnant; swelling; ready to give birth or produce.

“She was big with child.”

Used as an intensifier, especially of negative-valence nouns

“You are a big liar.  Why are you in such a big hurry?”

(of a city) populous

(of somebody's age) old, mature. Used to imply that somebody is too old for something, or acting immaturely.