1un·known 
/ˌʌnˈnoʊn/ adjective
/ˌʌnˈnoʊn/ adjective 1 : not known
▪ a disease of unknown cause/origin ▪ Much remains unknown about his early life. ▪ Her music was previously unknown outside of Asia. ▪ An unknown number of cases go unreported. ▪ The victim's attacker was unknown to her. ▪ For some unknown reason, my computer crashed. 2 : not well-known : not famous
▪ an unknown artist/writer ▪ a book of unknown poems
▪ a disease of unknown cause/origin ▪ Much remains unknown about his early life. ▪ Her music was previously unknown outside of Asia. ▪ An unknown number of cases go unreported. ▪ The victim's attacker was unknown to her. ▪ For some unknown reason, my computer crashed.
▪ an unknown artist/writer ▪ a book of unknown poems
unknown quantity — see quantity
unknown to
: without being known about by (someone)
▪ Unknown to me, my partner was organizing a surprise party for my birthday.
▪ Unknown to me, my partner was organizing a surprise party for my birthday.
