Submarine about to have a refit (1-4)
I believe the answer is:
u-boat
'submarine' is the definition.
(I know that U-boat is a type of attack submarine)
'about to have a refit' is the wordplay.
'about' says the letters should be written backwards.
'have' is an insertion indicator.
'refit' becomes 'bu' (I can't justify this - if you can you should believe this answer much more).
'to' enclosing 'a' is 'tao'.
'tao'+'bu'='taobu'
'taobu' in reverse letter order is 'U-BOAT'.
Can you help me to learn more?
(Other definitions for u-boat that I've seen before include "Submersible warship of WWII" , "Take pool exercise" , "German submarine of WW2" , "About (anag)" , "German wartime submarine" .)