Waving
Waving children in Somalia
Under Wave one will gesture understood that the visual greeting used or intended to attract the attention of other people. The hand is moved one or more times from left to right and back. The advantage of waving over acoustic greetings is that it is better perceived at great distances. Acoustic greeting and waving can also be combined with one another. As a greeting, you normally only wave with one hand. Waving with both hands is mostly used to attract attention.
Web links
Commons : Waving - collection of images, videos and audio files
Wiktionary: winken - explanations of meanings, word origins, synonyms, translations
