adjective. ['ˈtrɛmbəlɪŋ, ˈtrɛmblɪŋ'] vibrating slightly and irregularly; as e.g. with fear or cold or like the leaves of an aspen in a breeze.
noun. ['ˈtrɛmbəlɪŋ, ˈtrɛmblɪŋ'] a shaky motion.