せんぱい先輩senpai
1.

A person who holds a higher position or greater experience than oneself, often recognized for achievements in the same field or profession.

2.

An individual who entered a school or workplace before another, thus establishing a mentorship or guiding relationship.

3.

A fellow student or worker who graduated before you from the same institution, representing a connection to previous generations.

Example:

私たちは彼をよき先輩として尊敬している。

だいせんぱい大先輩daisenpai
1.

A person who has significantly more experience and seniority in a particular field or organization, often serving as a mentor or role model to those who are less experienced.

2.

An individual who has been involved in a profession or community for a long time, earning deep respect and recognition from peers due to their extensive knowledge and contributions.

3.

A senior figure or predecessor in a social or work setting, who is acknowledged not only for their age but also for their established authority and wisdom.