What is any character or figure which has, or is supposed to have, a hidden or mysterious significance; hence, any unintelligible or illegible character or mark. [Colloq.] called?

hieroglyphic — Any character or figure which has, or is supposed to have, a hidden or mysterious significance; hence, any unintelligible or illegible character or mark. [Colloq.]. (Webster's 1913.)

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