Looks at those approving loudly (4)
I believe the answer is:
eyes
'looks at' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for eyes that I've seen before include "Optical organs" , "Potato seed-buds" , "Closely looks at" , "They're said to be the mirrors of the soul" , "Ophthalmologist's speciality" .)