cnid-, cnido-

(Greek: nettle; a relationship to a nettle or nettle-like structure; nettle rash)

cnida
One of the peculiar stinging, cells found in Coelenterata (one of the major phyla of invertebrates, to which such forms as jellyfish belong); a nematocyst; a lasso cell.

A nematocyst is a stinging mechanism used for defense and to capture prey, by Hydra and other members of the Cnidaria (Coelenterata). It is located within a specialized cell, the nematocyte, and consists of a capsule containing a coiled tube.

cnidaria
A phylum of radially symmetrical invertebrates having a body composed of two layers of cells which consist of definite tissues. It includes hydroids (hydra), jellyfish, sea anemones, and corals.
cnidarian
1. Radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms.
2. Any invertebrate ocean animal that has tentacles surrounding the mouth; such as, sea anemones, corals, and jellyfish of the phylum Cnidaria.
cnidocyte
An ectodermal cell of Cnidaria (coelenterates) specialized for defense or capturing prey. Each cell has a nematocyst that can be replaced once discharged.
cnidophobia (s) (noun), cnidophobias (pl)
An excessive dread of being stung: Andrew refused to go on walks through forests, or even near one, because he had a fear of being bitten by insects or pricked by nettles or other plants, which his doctor diagnosed as a case of cnidophobia.
cnidosis; urticaria
A transient condition of the skin, usually caused by an allergic reaction, characterized by pale, or reddened, irregular, elevated patches and severe itching; hives.
cnidosis; urticaria
A transient condition of the skin, usually caused by an allergic reaction, characterized by pale, or reddened, irregular, elevated patches and severe itching, hives.