assistant professor; associate professor
Former official academic rank in Japan, roughly equivalent to assistant or associate professor. Replaced by 准教授 (じゅんきょうじゅ) in 2007, but still understood and sometimes used informally or in historical contexts.
彼は2005年に助教授に昇進した。
He was promoted to assistant professor in 2005.
Now the title 准教授 is used, but in the past it was called 助教授.
He became an assistant professor in his thirties.