n. [ NL., fr. Gr. &unr_;, neut. of &unr_; inactive; &unr_; priv. + &unr_; work. ] (Chem.) A colorless, odorless gas occurring in the air (of which it constitutes 0.93 per cent by volume), in volcanic gases, etc.; -- so named on account of its inertness by Rayleigh and Ramsay, who prepared and examined it in 1894-95. Symbol, A; at. wt., 39.9. Argon is condensible to a colorless liquid boiling at -186.1° C. and to a solid melting at -189.6° C. It has a characteristic spectrum. No compounds of it are known, but there is physical evidence that its molecule is monatomic. Weight of one liter at 0° C. and 760 mm., 1.7828 g. [ Webster 1913 Suppl. ]

n. [ L. Argonauta, Gr. &unr_;; &unr_; + &unr_; sailor, &unr_; ship. See Argo. ] 1. Any one of the legendary Greek heroes who sailed with Jason, in the Argo, in quest of the Golden Fleece. [ 1913 Webster ]

2. (Zool.) A cephalopod of the genus Argonauta. [ 1913 Webster ]

2. One of those who went to California in search of gold shortly after it was discovered there in 1848. [ U. S. ] Bret Harte. [ 1913 Webster ]

The “Argonauts of '49” were a strong, self-reliant, generous body of men. D. S. Jordan. [ Webster 1913 Suppl. ]

‖n. (Zool.) A genus of Cephalopoda. The shell is called paper nautilus or paper sailor. [ 1913 Webster ]

☞ The animal has much resemblance to an Octopus. It has eight arms, two of which are expanded at the end and clasp the shell, but are never elevated in the air for sails as was formerly supposed. The creature swims beneath the surface by means of a jet of water, like other cephalopods. The male has no shell, and is much smaller than the female. See Hectocotylus. [ 1913 Webster ]

a. [ L. Argonauticus. ] Of or pertaining to the Argonauts. [ 1913 Webster ]

n. 1. 1 a family of cephalopods represented solely by the genus Argonauta.
Syn. -- family Argonautidae. [ WordNet 1.5 ]

n. 1. an American operation in World War I (1918); American troops under Pershing drove back the German armies which were saved only by the Armistice on November 11.
Syn. -- Meuse, Meuse River, Argonne Forest, Meuse-Argonne, Meuse-Argonne operation [ WordNet 1.5 ]