At half fare, ten can be sent (3)
I believe the answer is:
fax
'be sent' is the definition.
I can't tell whether this defines the answer.
'at half fare ten' is the wordplay.
'at' is a charade indicator (letters next to each other).
'half' means to take half the letters.
'ten' becomes 'X' (Roman numeral).
'fare' cut in half is 'fa'.
'fa'+'x' is 'FAX'.
'can' is the link.
Can you help me to learn more?
(Other definitions for fax that I've seen before include "Means of communication" , "Transmission of exact copies of documents electronically" , "Electronic transmission" , "Transmit document" , "Modern method of transmitting printed matter by phone" .)