noun
regular conductor; permanent conductor
Refers to a conductor who holds a permanent or long-term position with an orchestra, choir, or similar ensemble, as opposed to a guest conductor.
彼はそのオーケストラの常任指揮者に就任した。
He was appointed as the regular conductor of the orchestra.
客演指揮者 is a guest conductor who appears for a limited engagement, while 常任指揮者 holds a permanent position.
Compound of 常任 (じょうにん, 'permanent, standing') and 指揮者 (しきしゃ, 'conductor').