Meaning of 相伝 in Japanese

Definition of 相伝

そうでん(souden) 【相伝】

いっしそうでん(isshisouden) 【一子相伝】

(n) transmission of the secrets of an art, craft, trade or learning from father to only one child
一子相伝の技と言うわりには、彼の蹴りは大した事はないね。
For a guy who was chosen by his father as the only son to be taught the secrets of this martial art, he doesn't have much of a kick.

ふしそうでん(fushisouden) 【父子相伝】

(n, adj-no) transmission of the secrets of an art, craft, trade or learning from father to son

ふだいそうでん(fudaisouden) 【譜代相伝】