صدو1 صَدْوٌ as an inf. n. of which the verb is صَدَا: see 2 in art. صدى, in two places.صَدْوٌ as a subst. A certain liquid poison which is applied upon arrow-heads, or spear-heads, or the like, resembling the blood of the [serpent called]أَسْوَد. (M, TA.)