The predator ate its prey.
The predator chased after its prey.
The glacier sat at the apex of the mountain. The shark is an apex predator.
The deer was wary of the predator following her.
The mountain lion is an apex predator.
A tiger is a very fierce predator since they eat other animals.
I am not writing a sentence using that word.
She was an opportunist, and thus never turned down any chance to get ahead.
I can give you a sentence using the word galaxy.
A predator stalks, hunts, and eats its prey.
This is a sentence using the word aviator.
a sentence using the word endotracheal
This is a sentence using the word monomer. :P