Parlance (5)
There are a few possibilities for this:
terminology
'parlance' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for idiom that I've seen before include "Characteristic style of a period" , "Language peculiar to a particular group" , "'Break a leg' or 'miss the boat'" , "Word usage peculiar to a specific group" , "Phrase such as over the moon" .)
'parlance' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lingo that I've seen before include "Language (slang)" , "Patois" , "Language (informally)" , "Tongue" , "Jargon, foreign language (informal)" .)
(Other definitions for terminology that I've seen before include "Nomenclature" , "Jargon" , "Phraseology" , "Special words" .)