A passage conductors take to their heart (4)
I believe the answer is:
duct
'a passage' is the definition.
(duct is a kind of passage)
'conductors take to their heart' is the wordplay.
'DUCT' is hidden within the letters.
But, I'm unsure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for duct that I've seen before include "Tube for cables, air, etc" , "Pipe, tube" , "The Eve of St - is a narrative poem by Keats" , "Pipe for cables or air" , "Pipe conveying fluid or gas" .)