Antiquity(noun) the quality of being ancient; ancientness; great age; as, a statue of remarkable antiquity; a family of great antiquity. Antiquity(noun) old age. Antiquity(noun) ancient times; former ages; times long since past; as, Cicero was an eloquent orator of antiquity.
Syllabic consonant. A syllabic consonant or vocalic consonant is a consonant that forms a syllable on its own, like the m, n and l in the English words rhythm, button and bottle, or is the nucleus of a syllable, like the r sound in the American pronunciation of work.
No comment on whether syllabus is a corrupted form. Since syllabus is from Greek not Latin, the prescriptively correct plural of syllabus is syllabontes. But no one would understand that, so we use the more familiar Latin-bi ending or plain ol' English-es plural in real life.