From Longman Dictionary of Contemporary Englishbalkybal‧ky /ˈbɔːki $ ˈbɒː-/ adjective especially American English informal REFUSEsomeone or something that is balky does not do what they are expected to do a balky air-conditioning system
Examples from the Corpus
balky• For one thing, the air conditioner in my hotel room is a bit balky.• The Toyota was sluggish and balky.• The engram bank may be balky but enough asking will bring forth any data in it sooner or later.• The theory is that his balky digestion -- gummed up by too much fruit -- will now return to normal.• The balky elevator has delivered the jumpers to a tiny platform contained within the tower.• The heat is balky in the winter.• Brown had been hobbled since training camp with a balky left knee that caused him pain from the second day of practice.• Dial-up connections were an afterthought, which is one of the reasons they tend to be so balky to use today. 