Crossword Genius

Tots creep unsettlingly into something no one should know about (3,6)

Ross

I believe the answer is:

top secret

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

'about' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?

'tots creep unsettlingly into something no one should know' is the wordplay.
'tots creep' can be anagrammed to 'TOP-SECRET'.
Though, I am not sure how this is indicated.

Can you help me to learn more?

(Other definitions for top secret that I've seen before include "Known to very few" , "Like highly guarded information" , "Very private" , "As 007 mission" , "the knack of sleeping well?" .)

I've seen this clue in the Sydney Morning Herald.
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.