Wasteful species destroy most of the division (11)
I believe the answer is:
spendthrift
'wasteful' is the definition.
(similar in meaning)
'species destroy most of the division' is the wordplay.
'species' becomes 'sp' (I've seen this in other clues).
'destroy' becomes 'end' (I've seen this in another clue).
'most of' means to remove the last letter.
'division' becomes 'rift' (I've seen this in another clue).
'the' with its final letter taken away is 'th'.
'sp'+'end'+'th'+'rift'='SPENDTHRIFT'
(Other definitions for spendthrift that I've seen before include "Prodigal" , "Profligate" , "Squanderer" , "Irresponsible user of money" , "Extravagant" .)