Fruit left behind is something highly prized (5)
I believe the answer is:
pearl
'something highly prized' is the definition.
I can't tell whether this defines the answer.
'fruit left behind' is the wordplay.
'fruit' becomes 'pear' (pear is a kind of fruit).
'left' becomes 'L' (common abbreviation).
'behind' means one lot of letters go next to another.
'pear'+'l'='PEARL'
'is' is the link.
Can you help me to learn more?
(Other definitions for pearl that I've seen before include "Oyster's gem" , "Lustrous structure in a mollusc shell" , "Highly-valued thing" , "Much loved and valued person" , "coming out of shell?" .)