Meaning of TRIVIAL in English
1》 of little value or importance.
2》 Mathematics denoting a subgroup that either contains only the identity element or is identical with the given group.
~ity noun ( plural ~ities ).
Trivial entered Middle English from Latin trivium 'place where three roads meet', from tri- 'three' and via 'road, way'. A medieval trivium was an introductory course at a university involving the study of grammar, rhetoric, and logic. In the Middle Ages seven ‘liberal arts’ were recognized, of which the trivium contained the lower three and the quadrivium the upper four (the ‘mathematical arts’ of arithmetic, geometry, astronomy, and music). This association with elementary subjects led to ~ being used to mean 'of little value or importance' from the 16th century.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004