What does "sneeze" mean?

Sneeze: To emit air, chiefly through the nose, audibly and violently, by a kind of involuntary convulsive force, occasioned by irritation of the inner membrane of the nose. Not to be sneezed at, not to be despised or contemned; not to be treated lightly. [Colloq.] "He had to do with old women who were not to be sneezed at." Prof. Wilson.