Bit of water brought in to lightly boil fish? (7)
I believe the answer is:
swimmer
'boil fish?' is the definition.
'swimmer' can be an answer for 'fish?' (I've seen this before). I am not certain of the 'boil' bit.
'bit of water brought in to lightly' is the wordplay.
'bit of' indicates taking the first letters.
'brought in to' indicates putting letters inside.
'lightly' becomes 'simmer' (I can't justify this - if you can you should give a lot more credence to this answer).
The first letter of 'water' is 'w'.
'w' put inside 'simmer' is 'SWIMMER'.
Can you help me to learn more?
(Other definitions for swimmer that I've seen before include "Michael Phelps, say" , "Eg, Captain Webb" , "fish" , "A mover in water" , "Person moving through water" .)