LIKE' (4 letters) FACEBOOK NUDGE is a feature on the social media platform Facebook that allows users to send a notification to another user. The two crossword solutions for this term are POKE (4 letters) and LIKE (4 letters). POKE is a feature on Facebook that allows users to send a notification to another user, while LIKE is a feature that allows users to show their appreciation for a post or comment. Both of these features are used to nudge another user on Facebook.