Friend runs away after suffering heart tremors (10)
I believe the answer is:
earthquake
'friend runs away' is the definition.
I can't tell whether this definition defines the answer.
'suffering heart tremors' is the wordplay.
'suffering' indicates an anagram.
'tremors' becomes 'quake' (I can't explain this - if you can you should believe this answer much more).
'heart' anagrammed gives 'earth'.
'earth'+'quake'='EARTHQUAKE'
'after' is the link.
Can you help me to learn more?
(Other definitions for earthquake that I've seen before include "Strong tremor" , "natural disaster" , "Seismic event" , "Violent tremor in ground" .)