Performing Lear, hit act gets histrionic (10)
I believe the answer is:
theatrical
'histrionic' is the definition.
('theatrical' can be similar in meaning to 'histrionic')
'performing lear hit act' is the wordplay.
'performing' indicates anagramming the letters.
'lear'+'hit'+'act'='learhitact'
'learhitact' is an anagram of 'THEATRICAL'.
'gets' acts as a link.
(Other definitions for theatrical that I've seen before include "Stagy" , "Actor" , "Artificial and exaggerated" , "affected" , "Relating to acting/actors" .)