Tackle hard friends and acquaintances (4)
I believe the answer is:
kith
'friends and acquaintances' is the definition.
(I've seen this before)
'tackle hard' is the wordplay.
'tackle' becomes 'kit' (both can mean gear or equipment).
'hard' becomes 'h'.
'kit'+'h'='KITH'
(Other definitions for kith that I've seen before include "Friends and neighbours, not family" , "Acquaintance" , "knowledge" , "'... and kin, friends and relations (4)'" , "Friends (archaic)" .)