Ignore unfriendly bear (4-8)
I believe the answer is:
cold-shoulder
'ignore' is the definition.
(giving someone the cold shoulder is ignoring them)
'unfriendly bear' is the wordplay.
'unfriendly' becomes 'cold' ('cold' can be similar in meaning to 'unfriendly').
'bear' becomes 'shoulder' (I've seen this before**).
'cold'+'shoulder'='COLD-SHOULDER'
(Other definitions for cold-shoulder that I've seen before include "Treat with indifference" , "Snub" , "Cut, ignore" , "Give (someone) a rebuff" , "Brush off" .)