Small bushy aromatic plant of the mint family. A small bushy aromatic herb of the genus Hyssopus (N.O. Labiatæ); spec. the common cultivated species H. officinalis, a native of Southern Europe, formerly much used medicinally, esp. in decoctions. In Biblical translations and derived use: A plant, the twigs of which were used for sprinkling in Jewish rites; hence, a bunch of this plant used in ceremonial purification, and allusively.