Rival industrial heads in pub - that's prickly (5)
I believe the answer is:
briar
'that's prickly' is the definition.
I can't tell whether this defines the answer.
'rival industrial heads in pub' is the wordplay.
'heads' says to take the initial letters.
'in' is an insertion indicator.
'pub' becomes 'bar' (both are drinking establishments).
The initial letters of 'rival industrial' is 'ri'.
'ri' inserted within 'bar' is 'BRIAR'.
Can you help me to learn more?
(Other definitions for briar that I've seen before include "Wild rose bush" , "Prickly scrambling shrub" , "Prickly wooden stem" , "Wood used for pipes" , "that one may smoke" .)