Secure drain pipe at last (4)
I believe the answer is:
tape
'secure drain' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'pipe at last' is the wordplay.
'pipe' becomes 'ape' (I am not sure about this - if you are sure you should believe this answer much more).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'last' becomes 't' (I've seen this in other clues).
'ape' after 't' is 'TAPE'.
Can you help me to learn more?
(Other definitions for tape that I've seen before include "String to be broken at end of a race" , "Adhesive --; red --" , "Magnetic recording medium; measuring strip" , "Breast this first to win foot-race" , "This is often stretched across the finishing line of race" .)