People in ads make up for past sins (6)
I believe the answer is:
amends
'up for past sins' is the definition.
I can't judge whether this definition defines the answer.
'people in ads' is the wordplay.
'people' becomes 'men' (men are people).
'in' indicates putting letters inside.
'men' put inside 'ads' is 'AMENDS'.
'make' is the link.
Can you help me to learn more?
(Other definitions for amends that I've seen before include "Frees from error" , "Make these to right wrong" , "Redress" , "Atonement" , "Makes changes, to a text say" .)