[せんか, senka] (n) (1) specialized course; specialised course; (2) something that is specialized for a certain field or application (e.g. a sauce specially made for zaru soba)#16205
[おやといがいこくじん, oyatoigaikokujin] (n) hired foreigners; foreign advisors hired by the Japanese government for their specialized knowledge to assist in the modernization of Japan at the end of the Bakufu and during the Meiji Era