Colander retains bananas and last bit of pear (8)
I believe the answer is:
strainer
'colander' is the definition.
(I know that strainer is a colander)
'retains bananas and last bit of pear' is the wordplay.
'bananas' indicates anagramming the letters (bananas can informally mean crazy).
'and' says to put letters next to each other.
'last bit of' indicates one should take the final letters.
The last letter of 'pear' is 'r'.
'retains' with letters rearranged gives 'straine'.
'straine'+'r'='STRAINER'
(Other definitions for strainer that I've seen before include "Tea-maker" , "one won't let everything go through" , "one that stretches?" , "Sieve, colander, etc" , "to collect leaves?" .)