Sly
din
A three-letter word that means "exist" is almost always "are." See if it will work.
A three-letter word ending in "ux" is "lux," which means a unit of illumination or light.
ado
The three later word that means view is see.
A three letter word that could mean clever is sly.
Observe means to see.
jab
see
hit
ilk
apt
See?
err
Par
e'er