Main Entry: break·through

Pronunciation: \ˈbrāk-ˌthrü\

Function: noun

Usage: often attributive

Date: 1918

1 : an offensive thrust that penetrates and carries beyond a defensive line in warfare
2 : an act or instance of breaking through an obstacle <a breakthrough agreement>
3 a : a sudden advance especially in knowledge or technique <a medical breakthrough> b : a person's first notable success <a breakthrough novel>