hand waving

noun

insubstantial words, arguments, gestures, or actions used in an attempt to explain or persuade.
Also hand-wav·ing, hand·wav·ing [hand-wey-ving] /ˈhændˌweɪ vɪŋ/.

Words nearby hand waving

hand to hand, hand to mouth, from, hand to on a silver platter, hand tool, hand truck, hand waving, hand's-breadth, hand, foot, and mouth disease, hand-carry, hand-deliver, hand-feed