also: だいい
captain (Army/USMC/USAF); lieutenant (Navy); flight lieutenant (RAF etc.)
Military rank; the exact equivalent depends on the service branch. The reading だいい was used by the Imperial Japanese Navy.
He was promoted to captain in the Army.
海軍の大尉が部下に命令を出した。
The navy lieutenant gave orders to his subordinates.
He was promoted to captain last year.
大尉 and 少佐 are adjacent military ranks that learners often mix up; 大尉 is captain while 少佐 is the higher major.
少尉 is the lowest commissioned officer rank, whereas 大尉 (captain/lieutenant) is a senior rank two steps above it, and the similar kanji make the two easy to confuse.
Used for people, especially in formal or seat/reservation contexts.
air force captain
Standard kanji form; the reading たいい is the most common.
Reading used historically by the Imperial Japanese Navy; not used in modern contexts.
From 大 (great) + 尉 (military officer rank). The reading だいい is a historical variant used by the Imperial Japanese Navy.