A defect in the hose used by firemen (6)
I believe the answer is:
ladder
This clue could be a double definition.
'a defect' is the first definition.
The answer and definition can be both related to natural events as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'hose used by firemen' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'in the' acts as a link.
Can you help me to learn more?
(Other definitions for ladder that I've seen before include "Domestic device for climbing" , "A fire-fighter may use one" , "Climbing frame; damage tights" , "squash club ranking?" , "sometimes with companion" .)