College in Orient sabotaged mass communications system (8)
I believe the answer is:
intercom
'communications system' is the definition.
(I've seen this before)
'college in orient sabotaged mass' is the wordplay.
'college' becomes 'c'.
'in' indicates putting letters inside.
'sabotaged' indicates an anagram.
'mass' becomes 'm' (symbol used in Physics e.g. f=ma).
'orient' is an anagram of 'intero'.
'c' put into 'intero' is 'interco'.
'interco'+'m'='INTERCOM'
(Other definitions for intercom that I've seen before include "Receiver" , "way to communicate" , "Means of transmitting messages" , "Two-way speaking device" , "Two-way communicator" .)