IPA: /ɪˈvɛntfəl/
KK: /ɪˈvɛntfəl/
Full of interesting or important events; having many significant occurrences.
Last summer was very eventful, with trips, parties, and new experiences.
Eventful → It is formed from "event" (from Old French *evenement*, meaning occurrence or happening) and "-ful" (meaning full of). The word "eventful" means full of events or occurrences.
Think of an 'event' being something that happens, and '-ful' means full of. So, an eventful day is one that is full of happenings.