la

Etymology 1

From Latin labii, from the first word of the sixth line of Ut queant laxis, the medieval hymn on which solfège was based because its lines started on each note of the scale successively.

noun

1. (music) A syllable used in solfège to represent the sixth note of a major scale.

Etymology 2

Sound used to form meaningless song refrains. Of imitative origin. Compare Old English lā (a common exclamation), Ancient Greek λαλαγε (lalage, “babble”), German lallen (“to babble”).

intj

1. Represents the sound of music or singing.
   "La la la la, I can't hear you!" Jimmy said, sticking his fingers in his ears.
   The only part Lucy had to sing was the interlude, which was a bunch of la la la's, and the last verse of the song, which was only four lines, and the chorus, which was just as short. 2019, Keira Brown, Between the Lines: Never in Plain Sight

Etymology 3

From Middle English la, from Old English lā. More at lo.

intj

1. (obsolete) Used to introduce a statement with emphatic or intensive effect.
2. (archaic) Expressing surprise, anger. etc.

Etymology 4

From French la, Italian la.

adj

1. Prefixed to the name of a woman, with ironic effect (as though an opera prima donna).
   Following lukewarm on the heels of an article a few weeks ago, where (I paraphrase due to having filed the relevant copy in the recycling bin) Victoria Beckham made a "well-meaning" remark that the other Spice Girls might want to lose a few pounds, we now have a new incidence of La Beckham's scintillating and entirely well-meaning humour. 22 Nov 2007, Kate Carter, The Guardian
   By judicious leaking, he also managed to make la Kirkpatrick and her associates look rather unsavory. 2010, Christopher Hitchens, Hitch-22, Atlantic, published 2011, page 232

Etymology 5

Possibly a shortened form of lad.

noun

1. (Liverpool) lad, kid