semi

¹ American  

[sem-ee, sem-ahy] / ˈsɛm i, ˈsɛm aɪ /

noun

Informal.

1. semitrailer.

2. Often semifinal.

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semi- ² American  

1. a combining form borrowed from Latin, meaning “half,” freely prefixed to English words of any origin, now sometimes with the senses “partially,” “incompletely,” “somewhat”.

   semiautomatic; semidetached; semimonthly; semisophisticated.

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semi ¹ British  

/ ˈsɛmɪ /

noun

1. a semidetached house

2. short for semifinal

3. short for semitrailer

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semi- ² British  

prefix

1. half Compare demi- hemi-

   semicircle

2. partially, partly, not completely, or almost

   semiprofessional

   semifinal

3. occurring twice in a specified period of time

   semiannual

   semiweekly

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semi– Scientific  

1. A prefix that means “half,” (as in semicircle, half a circle) or “partly, somewhat, less than fully,” (as in semiconscious, partly conscious).

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Usage

What does semi- mean? Semi- is a combining form used like a prefix meaning “half.” In some instances, it is used figuratively to mean "partially," "incompletely," or "somewhat." It is often used in a variety of technical and everyday terms.Semi- comes from Latin sēmi-, meaning “half.” The Greek cognate of sēmi- is hēmi-, also meaning “half,” which is the source of English terms such as hemialgia and hemicardia. To learn more, check out our entries for both words.

Commonly Confused

See bi- ¹.

Etymology

Origin of semi¹

By shortening

Origin of semi-¹

Middle English < Latin sēmi-; cognate with Old English sōm-, sām- half (modern dial. sam- ), Old High German sāmi-, Sanskrit sāmi-, Greek hēmi-; sesqui-

Example Sentences

The semis were played in Miami, the beating heart of the Cuban exile community.

From Washington Post

I laughed, "Mocha drip with extra foam, semi dry."

From Salon

"I remember it in the days when your face reflected in the polished floors, but now it's a semi derelict building," he said.

From BBC

Turner followed it with two more homers against Cuba in the semis, all while hitting ninth in the loaded U.S. order.

From Washington Post

Sinner, the 11th seed, advanced to the semis at a Masters 1000 for the second time.

From Seattle Times