Cordelia's father (4)
I believe the answer is:
lear
'cordelia's father' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lear that I've seen before include "Tragic Shakepearean king, for real" , "Tragic Shakespeare king - quite real" , "Tragic king in play" , "of poetry?" , "See 27 Across" .)