To peep; to pry into; to look at or spy on from a gap, a crack, or a hidden place.

leopard; panther; any of various large cats of the genus Panthera characterized by a spotted coat

one; the number 1; single; alone

trace; mark; stain; a small part of a whole as in the idiom 可见一斑 kě​jiàn​yī​bān