Label under meat dish reveals symbol (7)
I believe the answer is:
hashtag
'symbol' is the definition.
(social media symbol)
'label under meat dish' is the wordplay.
'label' becomes 'tag' (tag is a kind of label).
'under' says to put letters next to each other.
'meat dish' becomes 'hash' (type of meat dish).
'tag' put after 'hash' is 'HASHTAG'.
'reveals' acts as a link.
(Other definitions for hashtag that I've seen before include "Label on a message on Twitter" , "component of tweet" , "Word or phrase to aid online searches - hag's hat (anag)" , "Label on a Twitter post" , "Social media identifier" .)