n. (Hira=しつう) adultery, illicit intercourse, sexual relations with someone other than one's spouse

v. (Hira=しつうする) be in secret contact with somebody; commit adultery

v. (Trad=私通, Pinyin=si1 tong1) have secret communication

n. (Trad=私通, Pinyin=si1 tong1) illicit intercourse, adultery, liaison

v. (Simp=私通, Pinyin=si1 tong1) have secret communication

n. (Simp=私通, Pinyin=si1 tong1) illicit intercourse, adultery, liaison

[私通] (1) illicit intercourse; an illicit liaison [amour, love affair]; intimacy; fornication; adultery
(2) private correspondence (about public affairs); a private letter [note, message]

[私通-] (1) have an amour [affair] (with); have improper relations (with); establish illicit liaisons (with)
(2) correspond [keep a correspondence] (with a person) (about public affairs)