Give Heather ring, making kind of speech (5)
I believe the answer is:
Here is my best explanation:
'kind of speech' is the definition.
'give heather ring' is the subsidiary indication.
'give' means one lot of letters go next to another.
'heather' becomes 'ling' ('ling' can be a synonym of 'heather').
'ring' becomes 'o'.
'ling'+'o' is 'lingo'.
'making' is the link.
(Other definitions for lingo that I've seen before include "Jargon, language (colloq.)", "Tongue", "French?", "Language, colloquially speaking.", "Unfamiliar language or jargon", "Patois", "Language (colloq.)", "local dialect", "strange language" and "Johnny Foreigner speaks one".)