underhandedness рдХреНрдпрд╛ рд╣реИрдВ? underhandedness рдХреНрдпрд╛ рд╣реИрдВ? Acting or done in a deceptive, secret, or sly manner; dishonest and sneaky. See Synonyms at secret.Underhand: an underhanded toss.In a sly and secret way.With an underhand movement.