"Who winks with his eyes, who signals with his feet, who points with his fingers"
This verse is in the middle of a section of verses that runs from verse 12 to19 which deals with the worthless and/or wicked person. The idea is that there are characteristics that point out the person who is wicked. We should be alert to this kind of person so that we can avoid entanglements with this person whether business, romantic, or social. It is also a warning not to become this person.
This is the Hebrew word qaras which means to nip, pinch, wink. It might also be what we see as squinting. It is the clear indication that there is a way that the wicked person uses his eyes or looks that gives away an orientation to worthlessness or wickedness. This action or look signals that the person is being deceptive or radically selfish. Some have seen in this the wink that lets the gang know that they are going to deceive the potential victim. Others have seen in this expression the squinting of those who are unaccustomed to the light and do their work in the dark. Some have thought that this is more of a nervous twitch.
What is interesting about each of these signs of a wicked person is that they do not communicate openly but through shadowy signals and behind-the-back means. Only those in the know would understand what these things meant.
This is the word malal which means to rub, to scrape. It has been translated signal, scrape. There are two ideas that could be conveyed here: 1) that this person is actually trying to communicate to their friends with their feet; 2) that they are shuffling their feet signifying that they don't really have anything to do and are waiting to do harm or some nefarious activity.
This is the Hebrew word yara which means to throw, to shoot. It has been translated as point, shoot, instruct, teach. The idea is that some form of communication is taking place through hand signals.
In each case, in this verse the people are using secretive means of communication. Winking, scraping, and pointing are all forms of communication that must have been agreed upon ahead of time as to their meaning and/or are designed to hide communication to some or all of those that are around.
The sense that Solomon is trying to convey is that if you are around a person who is very given to secretive and hidden communication because they do not want everybody to have all the communication, something is wrong and most likely you are in the presence of a person who is, at best, worthless and could be wicked. For each of these forms of communication is for getting a message across while hiding that message to some in the group.
This happens in high school and junior high when the "in" crowd has all these signals to exclude the "out" crowd. They can, at times, fake including them only to ridicule them or use them. This happens in business as people in the office will exclude some from the real info. This happens as some businesses have hidden parts to a contract or agreement that they don't want others to know about. This happens in almost every group or organization as a person with selfish motives wants to put one over on others. Watch out for this – winking, feet signals, hand signals. Don't become like this. If you have to get your message across secretively rather than openly, is there a problem with the message or the goal?