No. You can only use alphanumeric characters and underscores in identifiers (variable, function, and type names) in C. And the identifier cannot start with a number. Also, you can’t use certain reserved keywords.
http://www.cprogrammingexpert.com/C/Tutorial/fundamentals/identifiers.aspx (link broken)
UPDATE: Newer link that’s not broken:
https://www.w3schools.in/c-programming/identifiers
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solved Can I use symbols, such as (*,/,&,^), for enum in C?