all day /ˌɔːlˈdeɪ/adverb 3all-day adjective 2 adverb3 •For the period of an entire day, or at least during all the daytime of a day.There hasn't been a breath of wind all day. •(figurative) Easily; handily; in spades; by far.Well, for twenty quid we're having it — it's worth that all day long. •(slang) In total.Table 2 needs three tacos, and Table 4 needs six, so that's nine tacos, all day. all-day adjective2 •Lasting throughout the whole day. •Available throughout the whole day.