Mistakes larger rat as smaller (6)
I believe the answer is:
errata
'mistakes' is the definition.
(an erratum is a mistake in a printed work)
'larger rat as smaller' is the wordplay.
'ERRATA' is hidden within the letters.
But, I'm uncertain how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for errata that I've seen before include "Text mistakes" , "corrected mistakes" , "Mistakes in printing or writing" , "Listed errors" , "Noted mistakes" .)