basil definition
basil - any of several Old World tropical aromatic annual or perennial herbs of the genus Ocimum. 1  herb, herbaceous plant - a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests. 2  genus Ocimum, Ocimum - basil. common basil, Ocimum basilicum, sweet basil - annual or perennial of tropical Asia having spikes of small white flowers and aromatic leaves; one of the most important culinary herbs; used in salads, casseroles, sauces and some liqueurs.