Nasty smell next to trap overwhelming a Czech (8)
I believe the answer is:
bohemian
'czech' is the definition.
(I've seen this before)
'nasty smell next to trap overwhelming a' is the wordplay.
'nasty smell' becomes 'B.O.' (abbreviation for body odour).
'next to' says to put letters next to each other.
'trap' becomes 'hemin' (I've seen this in another clue).
'overwhelming' is an insertion indicator.
'hemin' placed around 'a' is 'hemian'.
'bo'+'hemian'='BOHEMIAN'
(Other definitions for bohemian that I've seen before include "like Smetana?" , "Nonconformist" , "of old country" , "Unconventional person" , "Artistic, unconventional" .)