Source : Webster's Revised Unabridged Dictionary (1913)

Larghetto \Lar*ghet"to\, a. & adv. [It., dim. of largo largo.]
   (Mus.)
   Somewhat slow or slowly, but not so slowly as largo, and
   rather more so than andante.

Source : WordNet®

larghetto
     adj : (of tempo) less slow and broad than largo
     n : (music) a composition or passage played in a slow tempo
         slightly faster than largo but slower than adagio