Borrowed from Latin decimare, from decimus ("tenth").

• (RP) IPA: /ˈdɛsɪmeɪt/
• (America) IPA: /ˈdɛsəmeɪt/

decimate (decimates, present participle decimating; simple past and past participle decimated)

1. (archaic) To kill one-tenth of (a group), (historical, specifically) as a military punishment in the Roman army selected by lot, usually carried out by the surviving soldiers.

   Synonyms: tithe

   • c. 1650, Jeremy Taylor, Vol. I:

     God sometimes decimates or tithes delinquent persons, and they died for a common crime, according as God hath cast their lot in the decrees of predestination.

   • 1989, Basil Davidson, “The Ancient World and Africa”, in Egypt Revisited, page 49:

     Said to have been martyred as a Christian legionary commander of late Roman times for having refused an imperial order to kill one in ten (that is, decimate in the Roman meaning of the word) of the soldiers of another legion which had gone into revolt...

2. To destroy or remove one-tenth of (something).
3. (loosely) To devastate: to reduce or destroy significantly but not completely.
   • p. 1856, James Froude, History of England from the fall of Wolsey to the death of Elizabeth:

     [England] had decimated itself for a question which involved no principle, and led to no result.

   • 1996, Star Trek: Voyager (TV series), Flashback (episode)

     Um, some sort of power overload. I'm afraid it decimated your breakfast.

4. (obsolete) To exact a tithe or other 10% tax.
   • 1667 (revival performance), John Dryden, The Wild Gallant: A Comedy. […], In the Savoy [London]: […] T[homas] Newcomb for H[enry] Herringman, […], published 1669, Act II, page 18 ↗:

     You forge theſe things prettily; but I have heard you are as poor as a decimated Cavalier [referring to Cromwell's ten per cent. income-tax on Cavaliers], and had not one foot of land in all the vvorld.

5. (obsolete, rare) To tithe: to pay a 10% tax.
   • 1659, J[ohn] M[ilton], “To the Parlament of the Commonwealth of England with the Dominions therof ↗”, in Considerations Touching the Likeliest Means to Remove Hirelings out of the Church. […], London: […] T[homas] N[ewcombe] for L[ivewell] Chapman […], →OCLC ↗:

     [I]t is a deed of higheſt charitie to help undeceive the people, and a vvork vvorthieſt your autoritie, in all things els authors, aſſertors and novv recoverers of our libertie, to deliver us, the only people of all Proteſtants left ſtill undeliverd, from the oppreſſions of a Simonious decimating clergie; […]

     An adjective use.

6. (obsolete) To divide into tenths; to decimalize.
7. (proscribed) To reduce to one-tenth: to destroy or remove nine-tenths of (something).
8. (computer graphics) To replace (a high-resolution model) with another of lower but acceptable quality. (Usually algorithmically)
   • 1999, Mihalisin & al., "Visualizing Multivariate Functions, Data and Distributions" in Readings in Information Visualization: Using Vision to Think, page 122:

     A decimate tool allows us to obtain a more coarse-grained view of the data over the full n-dimensional space.

   • 2001, Inside 3Ds Max 4, page 56:

     However, many times it is more practical to decimate existing high-res models because of time, money or manpower issues.

   • 2004, Geremy Heitz et al., “Automatic Generation of Shape Models using Nonrigid Registration with a Single Segmented Template Mesh”, in Vision Modeling and Visualization 2004, page 74:

     Given this initial fine mesh, we smooth and decimate it to a desired mesh resolution.

• quintate
• centimate

• French: décimer
• German: dezimieren
• Italian: decimare
• Portuguese: dizimar

• Spanish: diezmar

• Portuguese: dizimar
• Russian: истребля́ть
• Spanish: diezmar

• German: verheeren, übel zurichten, zugrunde richten

decimate (plural decimates)

1. (obsolete) A tithe or other 10% tax or payment.
2. (obsolete) A tenth of something.
3. (obsolete) A set of ten items.