Meaning: an older brother
Recognized Reading: キョウ、ケイ、あに
兄弟(キョウダイ): a sibling (including sisters)
兄弟(ケイテイ): brothers
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!