Quick Definition: An opener that has a specific purpose within the given situation.
In addition to having a specific function in the venue, a functional opener can both be part true and part plausible deniability. This way, it does not seem as if the artist is hitting on the girl.
An example of a functional opener is “Excuse me. Do you know where the closest ATM is?” or “I’m new in town. Is there a good Japanese restaurant nearby?”
Sometimes, a functional opener is a great disqualifier to use with a really hot girl at a club to build social proof. Because she is very pretty (9s and 10s), your tonality and overall demeanor must be convincing.
See 5:16 in the video below on Adam Lyon’s street opener.
Keep in mind that a functional opener requires a strong transition and an indication that you are curious in talking to her beyond the original functional opener.