This character is a Other Symbol and is commonly used, that is, in no specific script. The character is also known as lounge.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+1F378 offers a line break opportunity at its position, except in some numeric contexts.
The CLDR project calls this character “cocktail glass” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: alcohol, bar, booze, club, cocktail, drink, drinking, drinks, glass, mad, martini, men.
This character is designated as an emoji. It will be rendered as colorful emoji on conforming platforms. To reduce it to a monochrome character, you can combine it with Variation Selector-15: 🍸︎ See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
A cocktail glass is a stemmed glass with an inverted cone bowl, mainly used to serve straight-up cocktails. The term cocktail glass is often used interchangeably with martini glass, despite their differing slightly. Today, the glass is used to serve a variety of cocktails, such as the martini and its variations (Gibson, French martini, vodka martini, espresso martini, appletini), Manhattan, Brandy Alexander, pisco sour, Negroni, cosmopolitan, gimlet, and the grasshopper.