Green’s Dictionary of Slang

lily adj.

[SE lily, i.e. white in colour]

SE in slang uses

In compounds

lily benjamin (n.) [benjamin n.1 ]

[mid-19C] a white greatcoat or overcoat.

lily shallow (n.)

[19C] a low-crowned white hat, esp. as worn by a coachman.

lily tile (n.)

[mid-19C] a white hat.

lily-tick (n.)

[mid-19C] (UK Und.) a silver watch.