prevalent (adj.)youdaoicibaDictYouDict[prevalent 词源字典]
early 15c., "having great power or force," from Latin praevalentem (nominative praevalens) "of superior strength; mighty," present participle of praevalere "to be more able" (see prevail). Meaning "extensively existing, in general use" is from 1650s.[prevalent etymology, prevalent origin, 英语词源]
sigil (n.)youdaoicibaDictYouDict
"a sign, mark, or seal," mid-15c., from Late Latin sigillum, from Latin sigilla (neuter plural) "statuettes, little images, seal," diminutive of signum "sign" (see sign (n.)). In astrology, an occult device supposed to have great power (1650s).
When my mistress died, she had under her arm-hole a small scarlet bag full of many things, which, one that was there delivered unto me. There was in this bag several sigils, some of Jupiter in Trine, others of the nature of Venus, some of iron, and one of gold, of pure angel-gold, of the bigness of a thirty-three shilling piece of King James's coin. ["The Antiquarian Repertory," London, 1780]