irksome
Annoying in a way that slowly bothers or tires you.
Irksome means annoying or irritating in a way that bothers you over time. It describes things that aren't terrible or dramatic, but they get under your skin and wear on your patience.
A squeaky desk chair that won't stop creaking is irksome. A classmate who constantly taps their pencil during silent reading is irksome. Having to explain the same thing over and over to someone who isn't listening can become irksome.
The word suggests a particular quality of annoyance: it's persistent and slightly draining, like a mild headache that won't quite go away. You might tolerate one irksome thing easily, but when several pile up (a flickering light, an itchy tag in your shirt, and someone chewing loudly), they can really test your patience.
Notice that irksome describes the thing doing the annoying, not your feeling about it. The task is irksome; you are irked by it. When something irks you, it bothers you in that particular grinding way. Some people find long car rides irksome, while others don't mind them at all. What's irksome to one person might not bother another, but everyone has something that irks them.