Public transport is almost bankrupt! (3)
I believe the answer is:
bus
'public transport' is the definition.
(bus is a kind of public transport)
'almost bankrupt' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'bankrupt' becomes 'bust' (I've seen this before).
'bust' with its final letter removed is 'BUS'.
'is' acts as a link.
(Other definitions for bus that I've seen before include "Coach" , "Of projectiles; (go) mad (slang)" , "Road vehicle able to carry many passengers" , "eg Double-decker" , "Charabanc" .)