Actual Gesture: with the thumb-side of the hand held near the mouth, waving it back and forth
It's Function?: It does as the name says, specifically when there's nothing the person doing it can do to help you out
Any Associated Phrase?: 2 main ones, the one for something being wrong, 「
Anything else?: You might see this paired with a shake of the head, just so you understand how little they can do for you. In addition, this can also used, as it is by folks in the West, to demonstrate the presence of disagreeable scents in the air-or in other words, that something stinks to high heaven(though it's not exactly in good taste to do it so blatantly). The context will tell you which is which, so be sure to check your scent, so you can start crossing off reasons the person might be making that gesture
Literal Meaning: What I'm doing is in bad form, but...
Intent: "Excuse me(and similar meanings in translation)"
1. To pardon yourself when you're something that interrupt what someone's doing(I.E. not being home when someone calls or leaving during the middle of meeting)
2. To excuse your when you have to go somewhere
3. To politely get someone's attention
Notes: 失礼, itself, is a な adjective that describes someone as being rude or impolite
(There's a guest waiting for me, so pardon the interruption)
(What does she mean by 'guest'?[note: in Japan, “Guest” can also carry the same connotations as 'Aunt Flo,' make of that what you will])