Understand wise words and vacillate (6)

I believe the answer is:

seesaw

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

'vacillate' is the definition.
(thesaurus)

'understand wise words' is the wordplay.
'understand' becomes 'see' (synonyms).
'wise words' becomes 'saw' (I can't justify this - if you can you should give a lot more credence to this answer).
'see'+'saw'='SEESAW'

'and' is the link.

Can you help me to learn more?

(Other definitions for seesaw that I've seen before include "Pivoted amusement" , "Move back and forth" , "entertainment for children" , "Playground device" , "Plank children play on" .)

I've seen this clue in The Sun.

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.