Distant handset (6)
I believe the answer is:
remote
'distant' is the definition.
(similar in meaning)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for remote that I've seen before include "TV control device" , "station selector?" , "Device for controlling apparatus from a distance" , "Detached" , "'Distant, out-of-the-way (6)'" .)