This is the 11513th most frequent Russian word.
досады
Annoyance or vexation.
In this sentence, 'досады' represents a feeling of annoyance or frustration, highlighting a subtle emotional state.
Он выразил нотку досады в своём голосе.
He expressed a hint of annoyance in his voice.
Here, 'досады' refers to the reason for his distraction, describing a state that affects his focus.
Из-за досады он никак не мог сосредоточиться на работе.
Due to annoyance, he could not concentrate on work at all.
In this context, 'досады' depicts an emotional undercurrent that the subject is trying to mask with a smile.