Question

what is this squigly line before a measure in music? what is the name and what does it mean? this is in Clair De Lune by Debussy​

Answer 1

An arpeggiated chord

Step-by-step explanation:

It means that you play the notes quickly in order and starting from the lowest note to the highest ( pitch wise) to create a sound almost like a harp.

I hope this helps!