せんこう専攻senkou
1.

The act of pursuing in-depth knowledge and expertise in a specific academic discipline or field of study.

2.

A designated area of focus within one's educational curriculum, emphasizing specialized training and research.

3.

The particular academic subject that a student selects to concentrate on, often determining their career path and future opportunities.

Example:

私はフランス語を専攻するつもりです。