Hieroglyphs or hieroglyphics can be

• characters from a logographic or partly logographic writing system, such as
  • Anatolian hieroglyphs (also known as Luwian hieroglyphs)
  • Cretan hieroglyphs
  • Mayan hieroglyphs (the best known of about half a dozen documented Mesoamerican writing systems)
  • Míkmaq hieroglyphic writing
  • Egyptian hieroglyphs

• colloquially, any handwritten characters which are difficult to read or decipher. (For example: "Bob, can you tell me what you've written here? I can't understand your hieroglyphics").

Etymology

The word hieroglyph derives from the Greek words ἱερός (hierós 'sacred') and γλύφειν (glúphein 'to carve' or 'to write', see glyph), and was first used to describe Egyptian hieroglyphs. The Greeks who came to Egypt prior to and during the Ptolemaic Period (305 BC - 30 BC) observed that while demotic script was employed for secular documents, pictorial characters were frequently found in religious contexts - carved on temple walls and funerary structures, as well as on official monuments.

The word "hieroglyphics" is derived from the fact that the Greeks called Egyptian hieroglyphs τά ἱερογλυφικά γράμματα 'hieroglyphic letters'; however, they sometimes simply dropped the "letters" part, calling them τά ἱερογλυφικά 'the hieroglyphics' ('letters' being understood).

While the adjective "hieroglyphics" is still used today by some as a noun and can add a humorous and informal tone (such as in the above example, in relation to remarks about the unreadability of a person's handwriting) this practice is technically incorrect.