Judd Hirsch sitcom (4)
I believe the answer is:
taxi
'judd hirsch sitcom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for taxi that I've seen before include "Part of fleet" , "Cab for hire" , "Vehicle with a meter" , "At airport, guide" , "move on ground before take-off" .)