/un"deuhr tohn'/ , n.
1. a low or subdued tone: to speak in undertones.
2. an unobtrusive or background sound: an undertone of static from the receiver.
3. an underlying quality or element; undercurrent: There was an undertone of regret in his refusal.
4. a subdued color; a color modified by an underlying color.
[ 1800-10; UNDER- + TONE ]