IPA: /ˈʌpərˌklæs.mən/
KK: /ˈʌpərˌklæs.mən/
A student who is in the third or fourth year of high school or college.
As an upperclassman, she had more responsibilities and leadership roles in the student council.
Upperclassman → It is formed from "upper" (from Old English "uper", meaning higher or above) and "classman" (from "class" derived from Latin "classis", meaning a group or division, and "man" meaning a person). The term refers to a student who is in a higher grade or year in school, indicating their advanced status compared to lowerclassmen.
Think of someone who is 'higher' ('upper') in their school 'class' — an upperclassman is simply a student in a higher grade.