la (1)

musical note (sixth note of the diatonic scale), early 14c., see gamut. It represents the initial syllable of Latin labii "of the lips." In French and Italian it became the name of the musical note A, which is the sixth of the natural scale (C major).

la (2)

fem. form of the French definite article, used in English in certain phrases and sometimes added ironically to a woman's name with a suggestion of "prima donna" (OED examples begin 1860s). See le.

la (3)

Anglo-Saxon interjection of mild wonder or surprise, or grief; "oh, ah, indeed, verily."

Definitions of la
la (n.)
a state in southern United States on the Gulf of Mexico; one of the Confederate states during the American Civil War;
Synonyms: Louisiana / Pelican State / La.
la (n.)
the syllable naming the sixth (submediant) note of a major or minor scale in solmization;
Synonyms: lah
La (n.)
a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth;
Synonyms: lanthanum / atomic number "