級友|きゅうゆうkyuuyuu[0]heiban (flat)

1. nounclassmate; friend in the same class
   彼かれは級友きゅうゆうからからかわれた。↗

   He was made fun of by his classmates.

• Synonym同級生どうきゅうせいNeutralCovers classmates in the same class or the same grade, so its range is broader; an everyday word. 「級友」 carries a sense of friendship with one's class and leans written.
• SynonymクラスメイトNeutralLoanword for classmates in the same class; common in speech and more casual than the written 「級友」.

For friends in the same class, 「級友」 is written/formal, as in 「かつての級友」. In everyday speech use 「同級生」; the loanword 「クラスメイト」 is the casual spoken choice.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 学校がっこうで同おなじ学級がっきゅうの友達ともだち。クラスメイト。