Picked up next to popular bar (5)
I believe the answer is:
ingot
'bar' is the definition.
(block of metal, eg a bar of gold)
'picked up next to popular' is the wordplay.
'picked up' becomes 'got' (I've seen this in another clue).
'next to' means one lot of letters go next to another.
'popular' becomes 'in' ('in' can mean trendy).
'got' put after 'in' is 'INGOT'.
(Other definitions for ingot that I've seen before include "A lump of metal like gold" , "Mass of metal, especially gold or silver" , "Block of precious metal" , "Moulded metal bar" , "Gold Stick" .)