This character is a Nonspacing Mark and inherits its script property from the preceding character.
The glyph is not a composition. Its width in East Asian texts is determined by its context. It can be displayed wide or narrow. In bidirectional text it acts as Nonspacing Mark. When changing direction it is not mirrored. U+0330 prohibits a line break before it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
The tilde () ˜ or ~, is a grapheme with a number of uses. The name of the character came into English from Spanish, which in turn came from the Latin titulus, meaning 'title' or 'superscription'. Its primary use is as a diacritic (accent) in combination with a base letter; but, for historical reasons, it is also used in standalone form within a variety of contexts.