*tonus*

‖n. [ NL., fr. Gr. &unr_; down + &unr_; (see Electro-) + &unr_; tone. ] (Physics) The condition of increased irritability of a nerve in the region of the cathode or negative electrode, on the passage of a current of electricity through it. [ 1913 Webster ]

‖n. [ NL., fr. combining form electro- + Gr. &unr_; tension. ] (Physiol.) The modified condition of a nerve, when a constant current of electricity passes through any part of it. See Anelectrotonus, and Catelectrotonus. [ 1913 Webster ]

‖n. [ NL., fr. E. galvanic + Gr. &unr_; to tone. ] (Physiol.) Same as Electrotonus. [ 1913 Webster ]

‖n. [ From the Indian name. ] (Zool.) The American badger. [ 1913 Webster ]

n. [ NL. See Photo-, and Tone. ] 1. (Bot.) A motile condition in plants resulting from exposure to light. -- Pho`to*ton"ic a. [1913 Webster]

2. (Physiol.) An irritable condition of protoplasm, resulting in movement, due to a certain intensity of light. -- Pho`to*ton"ic a. [ Webster 1913 Suppl. ]

‖n. [ NL., fr. Gr. pleyro`qen from the side + to`nos a stretching. ] (Med.) A species of tetanus, in which the body is curved laterally. Quain. Dunglison. [ 1913 Webster ]

n. [ NL.; thermo- + tonus. ] (Plant Physiol.) A condition of tonicity with respect to temperature. [ Webster 1913 Suppl. ]