It seems that there might be a small mistake in your request, as "amusd" does not appear to be a recognized English word. However, if you meant "AMusD," it stands for "Associate in Music, Doctorate," which is a degree in the field of music.
Here's a simple explanation of "AMusD":
AMusD (noun): A type of academic degree that signifies a high level of expertise in music, often awarded to individuals who have completed advanced studies and research in musical arts.