Became aware of misery engulfing king (4)
I believe the answer is:
woke
'became aware' is the definition.
(became conscious or aware)
'misery engulfing king' is the wordplay.
'misery' becomes 'woe' (woe is a kind of misery).
'engulfing' indicates putting letters inside.
'king' becomes 'k' (abbreviation for king in chess).
'woe' enclosing 'k' is 'WOKE'.
'of' acts as a link.
(Other definitions for woke that I've seen before include "Came to" , "Ceased to sleep" , "Stopped sleeping" , "Roused from sleep" .)