IPA: /ˈwɪərɪsəmnəs/
KK: /ˈwɛrɪsəmnəs/
The quality of being very tiring or boring, making someone feel exhausted or uninterested.
The wearisomeness of the long meeting made everyone eager to leave.
Wearisomeness → It is formed from "weary" (from Old English *werig*, meaning tired or fatigued) and "-some" (meaning causing or characterized by) and "-ness" (meaning the state or quality of). The word "wearisomeness" refers to the state of being tiresome or causing fatigue.
Think of feeling 'tired' ('weary') and how something can be 'causing' that tiredness ('-some'). This helps you remember that 'wearisomeness' means the quality of being tiresome.