A danger to shipping in Lough Foyle from the start (4)
I believe the answer is:
reef
'a danger' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'shipping in lough foyle from the start' is the wordplay.
'shipping in lough' becomes 'ree' (I can't justify this - if you can you should believe this answer much more).
'from the start' says to take the initial letters.
The initial letter of 'foyle' is 'f'.
'ree'+'f'='REEF'
'to' is the link.
Can you help me to learn more?
(Other definitions for reef that I've seen before include "Ridge of rock underwater" , "The sort of knot" , "offshore bank" , "Type of knot" , "Rocks in shallow water - kind of knot" .)