With figures about heart trouble tries to frighten (9)
I believe the answer is:
threatens
'with figures' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their -s form.
Maybe they are linked in a way I don't understand?
'heart trouble tries to frighten' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'heart' is 'threa' which is located in the answer.
The remaining letters 'tens' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'about' acts as a link.
Can you help me to learn more?
(Other definitions for threatens that I've seen before include "Intimidates with intention to harm" , "Imperils, jeopardises" , "Puts at risk" , "Utters intention to harm" , "Bullies" .)