IPA: /ˈvæpɪdli/
KK: /ˈvæpɪdli/
In a way that is dull, uninteresting, or lacking in flavor or excitement.
The lecture was delivered vapidly, leaving the students bored and uninterested.
Vapidly → It is formed from "vapid" (from Latin "vapidus", meaning flat or insipid) and the suffix "-ly" (meaning in a manner). The word "vapidly" means in a manner that is dull or lacking flavor.
Think of something that is 'flat' or 'insipid' ('vapid') and how it can be described as being done 'in a manner' ('-ly') that lacks excitement.