Other forms: classics
Something classic is so good and so typical of its kind that it never goes out of fashion. A classic film, a classic design, a classic mistake.
There are two threads here. One is lasting quality: a classic novel is one still read a century later. The other is typicality: a classic case, classic symptoms — meaning the textbook example, with no praise implied at all. As a noun, a classic is such a work; the classics are Greek and Latin literature. Note classical, which is a different word for music, architecture and antiquity, and is not interchangeable with classic.
1adjectiveclassicSo good and typical of its kind that it never dates.
“It is a classic design and it still sells.”
synonyms: timeless, definitive
2adjectivetextbookTypical; the textbook example.
“Those are the classic symptoms and nothing else fits.”
3nounworkA work of lasting quality.
“The book was a classic within about ten years.”
Too few real examples of this word to estimate which sense is commonest.
classic is a quality of lasting or typical excellence.
Also accepted in games: timeless
Latin classicus meant belonging to the highest class of Roman citizens. It came to mean first-rate, then first-rate in literature, and the school subject called classics preserves the ranking hidden inside the word.
French
classique
English, today
classic
Borrowed from French classique. From French classique, from Latin classicus (“relating to the classes of Roman citizenry, especially the highest”), from classis. by surface analysis, en + class + ic. classy.
Etymology from Wiktionary, CC BY-SA