昆弟 is read as こんてい (kontei) and means brothers.
こんてい
kontei
こぶ
kombu (usu. Saccharina japonica)
こんちゅう
insect
こんぶだし
soup stock made from kombu
こんめい
Kunming (China)
こんちゅうさいしゅう
insect collecting
ぎてい
brother-in-law (spouse's younger brother or younger sister's husband)
いとこ
cousin (male)
しゃてい
one's younger brother
さいじゅうてい
younger second cousin
きぎょうしゃてい
front company (for an organized crime operation)
ふたいとこ
second cousin
さんじゅうけいてい