In teeming rain, a compiler put on shirt: will this keep it off? (9)
I believe the answer is:
tarpaulin
'in teeming rain a compiler put on shirt will this keep it off?' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
I also know that 'rain' relates to this answer.
'in teeming rain a compiler put on shirt' is the wordplay.
'in' is an insertion indicator.
'teeming' indicates anagramming the letters.
'a compiler' becomes 'Paul' (Paul is a crossword compiler for the Guardian).
'put on' is a charade indicator (letters next to each other).
'shirt' becomes 't' (as in a T-shirt).
'rain' with letters rearranged gives 'arin'.
'arin' enclosing 'paul' is 'arpaulin'.
'arpaulin' put after 't' is 'TARPAULIN'.
(Other definitions for tarpaulin that I've seen before include "Heavy waterproof canvas" , "waterproof material" , "Waterproof canvas used as covering" , "[SHHET]" , "sailor's hat" .)