Wiktionary
glass onion
n. A large hand blown glass bottle used aboard ships to hold wine or brandy.
Wikipedia
Glass Onion
"Glass Onion" is a song by the Beatles from their 1968 double-album The Beatles primarily written by John Lennon and credited to Lennon–McCartney. This is the first track on the album to feature Ringo Starr on drums. Starr briefly left the group during recording sessions for the album and was replaced on drums by Paul McCartney on both " Back in the U.S.S.R." and " Dear Prudence".
Usage examples of "glass onion".
It was surrounded by an aureole, a disc of milky light that looked as if it was constructed of complex layers, like a huge glass onion in the sky, filled with light.