Meaning of head-and-tail light

head'-and-tail' light"

Pronunciation: (hed'n tāl'), [key]
  1. a small South American characin fish, Hemmigrammus ocellifer, having shiny red eyes and tail spots, often kept in aquariums. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.