"That'll be — day!” (3)

I believe the answer is:

the

(Other definitions for the that I've seen before include "Article is quite definite" , "The most frequently occurring word in the Bible (and in this clue!)" , "15, 16 One given taste of own medicine" , "Last words of story" , "That particular one" .)

I've seen this clue in the King Feature Syndicate.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.