Diod Definition In Ho.; a diactine with a central kink; d. (and triods) of various sizes may develop from reduced calthrops; d. may be lophate (e.g., genera Plakinastrella, Plakortis, Placinolopha, Plakina); see also lophodiod; compare with triod. Photos Diod of Ho. Lophose dios of Ho. Lophose diod of Ho.