Meanings
- computingAn extension to the x86 CPU instruction set architecture, providing direct hardware support for advanced floating-point arithmetic operations (rather than requiring them to be emulated in software).
Origin
Named after the product designations of the coprocessors used to provide floating-point support on early x86 systems lacking hardware support for these instructions in the main processor: the 8087 (for the 8086/8088 CPU), 80287 (for the 80286 CPU), 80387 (for the 80386 CPU), and 80487SX (for the 80486SX CPU). The 80486DX CPU and later integrated the floating-point hardware into the main processor, but the name continued in use for this set of instructions. The x serves as a wildcard.
Full word history & related roots →Cite this entry
x87. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/x87
“x87.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/x87. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “x87,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/x87.
Source: x87 on Wiktionary, CC BY-SA 4.0.