sesqui-

American  

1. a combining form meaning “one and a half,” used in the formation of compound words.

   sesquicentennial.

---

sesqui- British  

prefix

1. indicating one and a half

   sesquicentennial

2. (in a chemical compound) indicating a ratio of two to three

   sesquioxide

---

Usage

What does sesqui- mean? Sesqui- is a combining form used like a prefix meaning "one and a half." It is occasionally used in scientific terms, especially in chemistry.Sesqui- comes from Latin and is equivalent to sēmis, meaning "half-unit," and -que, a suffix meaning "and." The Greek cognate of sēmis is hēmi-, meaning "half," which is the source of terms such as hemisphere. To learn more, check out our Words That Use article on the combining form hemi-.

Etymology

Origin of sesqui-

< Latin sēsqui- < *sēm ( i ) sque, equivalent to sēmis half-unit, semis + -que and (cognate with Greek té, Sanskrit ca, Gothic -uh )

Example Sentences

He has memories from growing up of visiting the park with family, but he never knew “Sesqui” had a campground.

From Washington Times

On a cool November morning - prime hiking weather - Hunter walked the trails of Sesqui with state parks Director Paul McCormack, discussing what’s become their shared mission: making state park campgrounds look more like the communities they serve.

From Washington Times

Its name: the Sesquicentennial Amphitheater, “Sesqui” for short.

From Washington Post

Sesqui-, Latin for one and a half; so Sesquipedalis, a foot and a half long.

From Project Gutenberg

If more than one compound be formed from the same two elements, the difference is shown by prefixing such words as mono-, di-, tri-, sesqui-, per-, sub-, &c., to the last part of the name, or the suffixes -ous and -ic may be appended to the name of the first element.

From Project Gutenberg