Furious movement based on one member supported by lunatic (7,3)
I believe the answer is:
hopping mad
'furious' is the definition.
(I've seen this before)
'member supported by lunatic' is the wordplay.
'member' becomes 'hopping' (I can't justify this - if you can you should believe this answer much more).
'supported by' says to put letters next to each other (in a down clue, some letters hold up others).
'lunatic' becomes 'mad' (I've seen this before).
'hopping'+'mad'='HOPPING-MAD'
'movement based on one' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for hopping mad that I've seen before include "like a kangaroo?" , "Extremely angry (colloq.)" , "In a terrible rage" , "Furious (as a frog?)" , "Wild" .)