Meaning: an older brother
Recognized Reading: キョウ、ケイ、あに
兄弟（キョウダイ）: a sibling (including sisters)
兄妹（ケイマイ）: older brother and younger sister
父兄（フケイ）: a parent, a guardian
長兄（チョウケイ）: the eldest brother
義兄（ギケイ）: an older brother-in-law (the husband of one’s older sister)
従兄（ジュウケイ）: an older male cousin
貴兄（キケイ）: This word can be used for “you” in a letter to a man
兄（あに）: one’s older brother
兄貴（あにき）:one’s older brother, a big brother figure (can be used to address that person).
Unofficial but common reading:
お兄さん（おにいさん）: an older brother
#兄 is the combination of 口 and 儿. While you have to write 口 first, 兄 is listed under the radical of #ひとあし（儿）. There seem to be many different theories how 兄 was formed but if you have an older brother who talks a lot, it may be easier to remember 兄 is somebody who is made of a mouth and legs!