Definition of trainboy:
(n) :
A multicoloured arch in the sky, produced by prismatic refraction of light within droplets of rain in the air.
(n) :
Any prismatic refraction of light showing a spectrum of colours.
(n) :
(often used with “of”) A wide assortment; a varied multitude.
(adj) :
Multicolored, especially if in rainbow order.
(adj) :
(attributive, chiefly US) Made up of several races or ethnicities, or (more broadly) of several cultural or ideological factions.
(adj) :
(attributive) LGBT.