Language that's somewhat lyrical (in gobbledygook) (5)
I believe the answer is:
lingo
'language' is the definition.
(lingo is a kind of language)
'somewhat lyrical in gobbledygook' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'LINGO' is hidden within 'lyrical in gobbledygook'.
'that's' acts as a link.
(Other definitions for lingo that I've seen before include "Parlance" , "local dialect" , "special words" , "Patois" , "Language (slang)" .)