noun
new disciple; new student; new apprentice
General term for a newly accepted follower or trainee in traditional arts, crafts, or disciplines.
彼は今年、華道の新弟子として入門した。
He entered as a new disciple of flower arrangement this year.
noun
newly accepted professional wrestler (sumo)
Specifically used in sumo for a newly recruited wrestler who has just joined a stable.
新弟子が初めて土俵に上がった。
The new wrestler stepped onto the ring for the first time.
新入生 is used for new students in schools, whereas 新弟子 is for traditional apprenticeship or sumo contexts.
Compound of 新 (new) and 弟子 (disciple, apprentice). The reading しんでし follows standard on'yomi for 新 and kun'yomi for 弟子.