Showed boredom (6)
I believe the answer is:
yawned
'showed boredom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yawned that I've seen before include "Gaped, with tiredness?" , "Demonstrated tiredness (or boredom!)" , "Gave mute oral sign of boredom" , "Showed tiredness or tedium" , "Showed that one was tired" .)