Tip of the iceberg

Origin of: Tip of the iceberg

Tip of the iceberg

This a metaphor for the smaller, perceptible part of something, especially a problem or difficulty, which is in fact much greater. According to the OED, first known usage of tip of the iceberg in this sense is American from 1916, but Merriam-Webster and others differ, and maintain the figurative usage of the expression is much newer and dates from the 1960s. The expression derives from the observation of floating icebergs, where typically only one eighth of their total mass, i.e. the tip, is visible above the surface.