Large spike in approval is preceded by brief career (7)
I believe the answer is:
obelisk
'brief career' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'large spike in approval is preceded' is the wordplay.
I cannot really see how this works, but
'large' could be 'l' and 'l' is found within the answer.
'is' could be 'be' and 'be' is found in the answer.
This explanation may well be incorrect...
'by' is the link.
Can you help me to learn more?
(Other definitions for obelisk that I've seen before include "Needle-like column" , "Square stone column that tapers" , "Four-sided tapering pillar" , "Tapering square stone monument" , "Cleopatra's Needle, perhaps?" .)