Noun

(en noun)

(arithmetic) An irrational number, especially one expressed using the ? symbol.

(linguistics) A voiceless consonant.

Noun

(-)

Waves that break on an ocean shoreline.

* 1883 ,

...perhaps it was the look of the island, with its gray, melancholy woods, and wild stone spires, and the surf that we could both see and hear foaming and thundering on the steep beach...

* 1898 , , (Moonfleet) Chapter 5

'But when the surf fell enough for the boats to get ashore, and Greening held a lantern for me to jump down into the passage, after we had got the side out of the tomb, the first thing the light fell on at the bottom was a white face turned skyward.

* {{quote-book

, page=12 , year=1900 , author=Joseph Grinnell , title=Birds of the Kotzebue Sound Region, Alaska citation , passage=It was alone, nervously alighting and flying short distances along the surf .}}

* {{quote-book

, page=248 , year=1941 , author=Raymond Russell Camp , title=Fishing the Surf citation , passage=In most instances the inshore holes or pockets along the surf do not produce as well as the cuts or sloughs between sand bars.}}

* {{quote-book

, page=181 , year=1963 , author=Vlad Evanoff , title=Spin Fishing citation , passage=Snook are found in rivers, canals, inlets and along the surf , especially around sand bars, tidal rips, jetties, bridges and piers.}}

(UK, dialect) The bottom of a drain.