A communication link in hotel use (7)
I believe the answer is:
hotline
'a communication link' is the definition.
'hotline' can be an answer for 'link' (I have seen 'critical link' mean 'hotline' so perhaps 'link' could also mean 'hotline'). I am not certain of the 'a communication' bit.
'in hotel use' is the wordplay.
'use' indicates anagramming the letters (I've seen 'used' mean this).
'in'+'hotel'='inhotel'
'inhotel' is an anagram of 'HOTLINE'.
Can you help me to learn more?
(Other definitions for hotline that I've seen before include "Former direct phone line between the White House and the Kremlin" , "Direct phone link" , "Direct phone access (for presidents?)" , "Important number to call" , "Special phone link" .)