also: ことてん
noun
A reference work covering a wide range of topics, similar to an encyclopedia. Often used in titles like 〇〇事典.
この事典は歴史の項目が充実している。
This encyclopedia has extensive entries on history.
Rare reading; the usual reading is じてん.
Compound of 事 (thing, matter) and 典 (reference work, code). The reading じてん is the standard Sino-Japanese reading; ことてん is a rare mixed reading.