[adj] expressed without speech; especially because words would be inappropriate or inadequate; "a mute appeal"; "a silent curse"; "best grief is tongueless"- Emily Dickinson; "the words stopped at her lips unsounded"; "unspoken grief"; "choking exasperation and wordless shame"- Thomas Wolfe
[adj] lacking power of speech
[adj] lacking a tongue; "tongueless moccasins"