Existed in fewer examples (4)
I believe the answer is:
were
'existed' is the definition.
(I've seen this before)
'in fewer examples' is the wordplay.
'in' indicates a hidden word.
'WERE' is hidden in the letters of 'fewer examples'.
(Other definitions for were that I've seen before include "'Are, in the past (4)'" , "SECOND PART OF 9" , "Used to be" , "SECOND PART OF 14" , "(You/we/they) existed" .)