Definition from Wiktionary, the free dictionary
- (idiomatic) A word or phrase that is used to describe multiple groups of related things. The degree of relation may vary. Blanket terms often trade specificity for ease-of-use; in other words, a blanket term by itself gives little detail about the things that it describes or the relationships between them, but is easy to say and remember. Blanket terms often originate as slang, and eventually become integrated into the general vocabulary.
Usage notes 
- Racial groupings such as White, Asian, and Black
- Personal computer, IBM PC, or IBM PC compatible, for any computer modeled upon the x86 architecture
- Car, for automobiles, trucks, and similar vehicles.
- iPod or MP3 player for any type of digital audio player.