Shrewd lot of wives put money first being considered mad (5,4)
I believe the answer is:
march hare
'considered mad' is the definition.
I can't judge whether this defines the answer.
'shrewd lot of wives put money first' is the wordplay.
'shrewd' becomes 'arch' (I've seen this before).
'lot of' means to remove the last letter (a lot of the word but not all of it).
'wives' becomes 'harem' (I've seen this before).
'put money' becomes 'm' (I am not sure about this - if you are sure you should believe this answer much more).
'first' says to put letters next to each other.
'harem' with its final letter taken off is 'hare'.
'arch'+'hare'='archhare'
'archhare' put after 'm' is 'MARCH HARE'.
'being' acts as a link.
Can you help me to learn more?
(Other definitions for march hare that I've seen before include "Character at the tea-party in Alice's Adventures in Wonderland" , "seen at endless party" , "Animal in state of wild behaviour, starting with 3rd month?" , "Supposedly mad creature" , "character encountered by Alice" .)