Yankee with beard looked bored (6)
I believe the answer is:
yawned
'looked bored' is the definition.
'yankee with beard' is the wordplay.
'yankee' becomes 'y' (phonetic alphabet: alpha, bravo, charlie etc.).
'with beard' becomes 'awned' (an awn is a type of 'beard' growth in botany).
'y'+'awned'='YAWNED'
(Other definitions for yawned that I've seen before include "Gave mute evidence of boredom" , "Gaped, wide open" , "Gaped, with tiredness?" , "Showed signs of tiredness" , "Gave visible sign of boredom - or tiredness" .)