Learner's definition of ANNOYANCE
1 [noncount] : slight anger : the feeling of being annoyed
She expressed annoyance at the slow service.
They were late again, (much) to our annoyance. [=it annoyed us that they were late again]
She shook her head in annoyance. [=in a way that showed she was annoyed]
2 [count] : something that causes feelings of slight anger or irritation : a source of annoyance