Capable of being irritated. / Easily exasperated or excited. / (medicine) Responsive to stimuli.

a solid consisting of a double twelve-sided pyramid

(mineralogy) A hexagonal-dihexagonal dipyramidal bright yellow mineral containing calcium, hydrogen, manganese, oxygen, and silicon.

(dated, electronics) A unit of capacitance equal to one billion (10⁹) farads, used in the centimeter-gram-second system of units