覗く （のぞく） to peek (through a keyhole, gap, etc.), to look down into (a ravine, etc.), to peek into (a shop, bookstore, etc.), to sneak a look at, to take a quick look at, to peep (through a telescope, microscope, etc.), to stick out (a scarf from a collar, etc.), to peek through (sky through a forest canopy, etc.), to examine (an expression), to study (a face), to face

窺う （うかがう） to peep (through), to peek, to examine (esp. covertly), to await (one's chance), to guess, to infer, to gather, to surmise