Here are the possible solutions for what you might use to put on a happy face clue
Answer
Clue
Relevancy
emoji
Clue
What you might use to put on a happy face?
Definition
(Japanese) a standardized image with a specific meaning, used in electronic communication
stumps
Clue
Baffles (ABOUT THIS PUZZLE: If you saw the headline "Fiend Found!" you might instantly notice that, between the two words, only the vowels change — the consonants stay put. Okay, if you were me, you'