Last of intake failing to pass (6)
I believe the answer is:
elapse
'pass' is the definition.
(I've seen this before)
'last of intake failing' is the wordplay.
'last of' says to take the final letters.
'failing' becomes 'lapse' (I've seen this before).
The final letter of 'intake' is 'e'.
'e'+'lapse'='ELAPSE'
'to' acts as a link.
(Other definitions for elapse that I've seen before include "'Pass by, as time (6)'" , "Please (anag) -- pass away" , "Go by - pass away" , "run by" , "Glide by" .)