semi

plural semis

1. AustraliaCanadaIrelandUKinformalA semi-detached house.

   2008, Elliott Placks, quoted in Helen Isbister, Morris Bryant, Property, Career FAQs, Australia, page 40, I′m selling two side-by-side semis that are currently under construction, a waterfront apartment and a house in Rose Bay.

   2 more examples

   The smaller semis of the 1920s and 1930s were closely related to the three bedroom pre-1919 narrow fronted terraces, at least to the larger pre-1919 terraces.

   2008, Barry Goodchild, Homes, Cities and Neighbourhoods: Planning and the Residential Landscapes of Modern Britain, page 52

   The roads were lined with cramped little semis and 1960s bungalows: Britain's cheapest houses, in their flimsy, pebble-dashed glory.

   2012, Tim Moore, You Are Awful (But I Like You): Travels Around Unloved Britain, Vintage, →ISBN, page 150

2. AustraliaCanadaNew ZealandUSA semi-trailer; a tractor-trailer; an eighteen-wheeler; an artic.

   I was hungry an' freezin' an' done caught a chill / When the lights of a big semi topped the hill

   1967, Tommy Faile, “Phantom 309”, performed by Red Sovine

   1 more example

   All night we couldn′t hear each other speak because of the sound of semis changing gear to get over the hill.

   2011, Eamonn Duff, Schapelle Corby: The Untold Story Behind Her Ill-Fated Drug Run, Australia: Allen & Unwin, unnumbered page

3. informalA semifinal.
4. slangA partial erection of the penis.

   The twink got a semi just from that look.

   2010, Mickey Erlach, Video Boys, page 158

5. slangA semiautomatic firearm.

   See these niggas through the reticle sight up on my semi […] For niggas plottin', I might blow it at your fitted Get your bitch-ass slimed out, it ain't no kiddin' Ain't no kiddin', got that semi

   2023 April 28, “Got Dat Muneh” (track 10, 0:48 from the start), in Summrs (lyrics), GHOST

6. slangbusinessSemiconductor companies or positions in the stock market.
7. colloquialbusinessAn intermediate in the production of end-use goods.

   1 more example

   Mining companies crush and grind the extracted ore, and then use flotation processes to produce copper concentrates, which typically contain up to 30 percent copper. These concentrates are then smelted to produce copper blister, which has a purity of up to 99 percent. The blister is further refined to produce copper cathode, or pure copper, with a grade of around 99.99 percent. This process is known as pyrometallurgy, and is suitable for sulfide ores as opposed to oxide ores. The pure copper then feeds into the fabrication of various copper products, such as wire rods, wires, bars, and sheets—collectively known as semis—used as inputs in the manufacturing of end-use products, including consumer goods and construction, transportation (e.g., EVs) and infrastructure components.

   2025 April 1, Dorjdari Namkhaijantsan, Zoljargal Naranbaatar, “Copper and the energy transition”, in Copper Sector Expansion in Mongolia: Opportunities and Challenges, Natural Resource Governance Institute, page 13 of 10–26

1. informalnot comparableSomewhat; to some extent.

   'Is that a serious question?' he asked. Ralph shrugged with his face, jutting out his bottom lip. 'Well ... semi,' he said.

   2013, Mark Morris, The Secret of Anatomy