Obtain inner satisfaction (3)

I believe the answer is:

eat

I'm a little stuck... Click here to teach me more about this clue!

'obtain' is the definition.
The answer and definition can be both related to change as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for eat that I've seen before include "Make food disappear" , "Take food" , "tolerate in diet" , "Have 23d [MEAL]" , "Corrode" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.