Left route before wrong turning in Welsh town (8)
I believe the answer is:
'welsh town' is the definition.
(I've seen this before)
'left route before wrong turning' is the wordplay.
'left' becomes 'l' (common abbreviation).
'route before' becomes 'lane' (type of road. I am not sure about the 'before' bit.).
'wrong' becomes 'ill' (I've seen this in another clue).
'turning' is a reversal indicator.
'ill' written backwards gives 'lli'.
'in' is the link.
Can you help me to learn more?
(Other definitions for llanelli that I've seen before include "Welsh town" , "Welsh place" , "Town NW of Swansea" , "Port in Dyfed" , "Carmarthenshire town; an ill ell (anagram)" .)