Source : Webster's Revised Unabridged Dictionary (1913)

Argonaut \Ar"go*naut\, n.
   One of those who went to California in search of gold shortly
   after it was discovered there in 1848. [U. S.] --Bret Harte.

         The ``Argonauts of '49'' were a strong, self-reliant,
         generous body of men.                    --D. S.
                                                  Jordan.

Argonaut \Ar"go*naut\, n. [L. Argonauta, Gr. ?; ? + ? sailor, ?
   ship. See {Argo}.]
   1. Any one of the legendary Greek heroes who sailed with
      Jason, in the Argo, in quest of the Golden Fleece.

   2. (Zo["o]l.) A cephalopod of the genus Argonauta.

Source : WordNet®

argonaut
     n 1: someone engaged in a dangerous but potentially rewarding
          adventure
     2: (Greek mythology) one of the heroes who sailed with Jason on
        the Argo in search of the Golden Fleece
     3: cephalopod mollusk of warm seas whose females have delicate
        papery spiral shells [syn: {paper nautilus}, {nautilus}, {Argonauta
        argo}]