Actinia, ak-tin′i-a, n. a genus of marine animals of the class Polypi, growing on rocks or shells, with numerous tentacles or rays like the petals of a flower, from which they are often called animal flowers or sea-anemones. [From Gr. aktis, aktinos, a ray.]
Actiniform, ak-tin′i-form, adj. having a radiated form. [Gr. aktis, aktinos, ray, and Form.]
Actinism, ak′tin-izm, n. the chemical force of the sun's rays, as distinct from light and heat.—adj. Ac′tinic. [Gr. aktis, aktinos, a ray.]
Actinolite, ak-tin′ō-līt, n. a green variety of hornblende. [Gr. aktis, aktīnos, a ray, lithos, a stone.]
Actinometer, ak-tin-om′e-tėr, n. an instrument for measuring the heat-intensity of the sun's rays or the actinic effect of light-rays. [Gr. aktis, aktinos, ray, and Meter.]
Actinomyces, ak-ti-no-mī′sez, n. the tiny ray-fungus.—n. Actinomycō′sis, an inflammatory disease in cattle, swine, and sometimes man, caused by that fungus. [Gr. aktis, aktinos, ray, and myces, mushroom.]
Actinozoa, ak′tin-ō-zō′a, n.pl. one of the three classes of Cœlenterata, including sea-anemones, dead-men's fingers, corals, &c. [Gr. aktis, -inos, a ray; zōa, animals.]
Action, ak′shun, n. a state of acting: activity in the abstract: a deed: operation: gesture: a battle: a lawsuit, or proceedings in a court: the movement of events in a drama, novel, &c.—adj. Ac′tionable, liable to a lawsuit.—n. Ac′tion-tak′ing (Shak.), resenting an injury by a lawsuit instead of fighting it out like a man of honour.
Activate, ak′ti-vāt, v.t. (Bacon) to make active:—pr.p. ac′tivāting; pa.p. ac′tivāted.
Active, akt′iv, adj. that acts: busy: nimble: practical, as opposed to speculative: effective: (gram.) transitive.—adv. Act′ively.—ns. Activ′ity, Act′iveness.