Gakkyūiin (学級委員, Gakkyūiin?), or Gakkyūiinchō (学級委員長, Gakkyūiinchō?), is a Japanese term meaning class representative, in the context of elementary school and junior high school, and is commonly referred to by the shortened title "Iinchō". Alternatives include Class Iinchō (クラス委員長, kurasuiinchō?) or Kurasuiin (クラス委員, Kurasuiin?).

In anime, the class iinchō is commonly depicted as a bespectacled girl (meganekko) or boy with a pushy albeit well-meaning attitude. Often the character is addressed by this title instead of their by their own name. Examples include:

Source: Wikipedia