MacSymbol (Symbol Typeface) is a character encoding / character set / typeface / font (the distinctions between these were fuzzier in those days) used on classic Mac OS. As with MacDingbats, it's a specialized set of symbols not including normal ASCII letters, though it's not so whimsical as Dingbats; it mostly has symbols used in mathematics. The Greek alphabet is included, but intended for math rather than writing in Greek (the accented versions aren't included); MacGreek is intended for actual Greek use.
This derives from an Adobe Symbol font, but Apple put an Apple logo in position F0, which shows up in code charts as Unicode private use code point F8FF.
See Macintosh encodings for related encodings.