high-water mark

[hahy-waw-ter, -wot-er]

noun

1. a mark showing the highest level reached by a body of water.

2. the highest point of anything; acme.

   Her speech was the high-water mark of the conference.

high-water mark

noun

1. 1. the level reached by sea water at high tide or by other stretches of water in flood

   2. the mark indicating this level

2. the highest point

Word History and Origins

Origin of high-water mark¹

First recorded in 1545–55

Idioms and Phrases

The peak of something, especially an achievement. For example, This composition is the high-water mark of his entire output. This expression alludes to the highest mark left on shore by the tide. [Mid-1800s]

Related Words

• apex 
• apogee 
• upper limit www.thesaurus.com