IPA: /ˈdeɪlɔŋ/
KK: /deɪlɔŋ/
Continuing or occurring throughout the entire day.
We had a daylong meeting to discuss the project.
For the entire day; throughout the whole day.
We had a daylong meeting to discuss the project.
Daylong → It is formed from "day" (from Old English "dæg", meaning a period of 24 hours) and "-long" (meaning lasting for a specified duration). The word "daylong" means lasting for the entire duration of a day.
Think of a period of 24 hours ('day') that lasts 'long' — that's why daylong means lasting the whole day.