In Omaha, hardly a barrier? (2-2)
I believe the answer is:
ha-ha
'barrier?' is the definition.
(I've seen this before)
'in omaha hardly a' is the wordplay.
'in' indicates a hidden word.
'HA-HA' is hidden in the letters of 'omaha hardly a'.
(Other definitions for ha-ha that I've seen before include "Sunk ditch - laugh!" , "Sunken boundary wall" , "Ditch with wall in it - sounds hilarious" , "Kind of ditch with wall in it" , "Sunk fence" .)