Don’t allow to catch up (3)
I believe the answer is:
ban
'don't allow' is the definition.
(I've seen this in another clue)
'catch up' is the wordplay.
'catch' becomes 'nab' (nab can mean to capture or arrest).
'up' is a reversal indicator (in down clue: letters go upwards).
'nab' reversed gives 'BAN'.
'to' is the link.
(Other definitions for ban that I've seen before include "outlaw" , "Censor or proscribe" , "Bar, prohibition" , "Hungarian governor < to forbid" , "Officially prohibit" .)