Princeton's WordNet

1. lanthanum, La, atomic number 57(noun)

   a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth

   Synonyms:
   atomic number 57, lanthanum, lah

2. Louisiana, Pelican State, LA(noun)

   a state in southern United States on the Gulf of Mexico; one of the Confederate states during the American Civil War

   Synonyms:
   atomic number 57, lanthanum, lah

3. la, lah(noun)

   the syllable naming the sixth (submediant) note of a major or minor scale in solmization

   Synonyms:
   atomic number 57, lanthanum, lah, la