Games a police chief overheard in thick fog (3-6)
I believe the answer is:
pea-souper
'thick fog' is the definition.
(I've seen this before)
'games a police chief overheard in' is the wordplay.
'games' becomes 'PE' (Physical Education, also called games).
'police' becomes 'super' (I can't justify this - if you can you should believe this answer much more).
'chief' suggests taking the first letters.
'in' indicates putting letters inside.
The first letter of 'overheard' is 'o'.
'super' enclosing 'o' is 'souper'.
'pe'+'a'+'souper'='PEA-SOUPER'
Can you help me to learn more?
(Other definitions for pea-souper that I've seen before include "Thick, dirty, yellowish fog" , "Dense, dirty fog" , "Thick smokey fog" , "Dense yellow fog" .)