semi

1 of 4

noun (1)

plural semis
: semifinal
often used in plural

semi

2 of 4

noun (2)

plural semis

semi

3 of 4

noun (3)

plural semis
chiefly British
: a semidetached house

semi-

4 of 4

prefix

ˌse-mē,
-ˌmī,
-mi
1
a
: precisely half of:
(1)
: forming a bisection of
semidiameter
(2)
: being a usually vertically bisected form of (a specified architectural feature)
semidome
b
: half in quantity or value : half of or occurring halfway through a specified period of time
semiannual
semimonthly
compare bi-
2
: to some extent : partly : incompletely
semicivilized
semi-independent
semidry
compare demi-, hemi-
3
a
: partial : incomplete
semiconsciousness
semidarkness
b
: having some of the characteristics of
semiporcelain
c
: quasi-
semigovernmental
semimonastic

Examples of semi in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
The 20-year-old is seen as the poster boy for Turkey’s hopes of a first World Cup appearance since a famous run to the semi-finals in 2002. Jack Bantock, New York Times, 4 Sep. 2025 But the semi-romance that should elevate the plot to a higher level of emotionality has, instead, the opposite effect. Angie Han, HollywoodReporter, 30 Aug. 2025 According to one Tennessean article, four semi-trailers full of supplies, including bedding, appliances and more than 700 food boxes that could each feed a family of four for a week, were on stand-by from the Church of Christ Disaster Relief Effort in Nashville the day before the storm. Angele Latham, The Tennessean, 29 Aug. 2025 The Toxic Avenger, a semi-reboot of the 1984 superhero splatter-fest, made the rounds of the festival circuit back in 2023. Jennifer Ouellette, ArsTechnica, 25 Aug. 2025 See All Example Sentences for semi

Word History

Etymology

Noun (3)

short for semidetached

Prefix

Middle English, from Latin; akin to Old High German sāmi- half, Greek hēmi-

First Known Use

Noun (1)

1942, in the meaning defined above

Noun (2)

1942, in the meaning defined above

Noun (3)

1912, in the meaning defined above

Time Traveler
The first known use of semi was in 1912

Browse Nearby Words

Cite this Entry

“Semi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/semi. Accessed 9 Sep. 2025.

Kids Definition

semi-

prefix
ˌsem-i,
ˈsem-,
-ˌī
1
: half in amount or value
semitone
2
: occurring halfway through a certain time period
semiannual
3
: to some extent : partly : incompletely
semitropical
4
: partial : incomplete
semidarkness
Etymology

Prefix

Latin semi- "half"

More from Merriam-Webster on semi

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!