Displayed boredom (6)
I believe the answer is:
yawned
'displayed boredom' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for yawned that I've seen before include "Opened mouth wide as expression of boredom" , "Showed tiredness or boredom" , "Showed that one was tired" , "Demonstrated tiredness (or boredom!)" , "Gave mute evidence of boredom" .)