# ISR

> English word · Noun · frequency rank #49,434

## Definitions
1. Initialism of interrupt service routine.
2. Initialism of intelligence, surveillance, reconnaissance (“spycraft”).
3. Initialism of interstate route.

## Easily confused with
- **it** (https://plainspell.com/en/vs/isr-vs-it)
- **IV** (https://plainspell.com/en/vs/isr-vs-iv)
- **iz** (https://plainspell.com/en/vs/isr-vs-iz)
- **its** (https://plainspell.com/en/vs/isr-vs-its)
- **ivy** (https://plainspell.com/en/vs/isr-vs-ivy)
- **ISS** (https://plainspell.com/en/vs/isr-vs-iss)
- **IVF** (https://plainspell.com/en/vs/isr-vs-ivf)
- **itt** (https://plainspell.com/en/vs/isr-vs-itt)
- **ITC** (https://plainspell.com/en/vs/isr-vs-itc)
- **isu** (https://plainspell.com/en/vs/isr-vs-isu)
- **Ivo** (https://plainspell.com/en/vs/isr-vs-ivo)
- **IWC** (https://plainspell.com/en/vs/isr-vs-iwc)
- **ith** (https://plainspell.com/en/vs/isr-vs-ith)
- **issa** (https://plainspell.com/en/vs/isr-vs-issa)
- **Ivor** (https://plainspell.com/en/vs/isr-vs-ivor)
- **Iver** (https://plainspell.com/en/vs/isr-vs-iver)
- **i** (https://plainspell.com/en/vs/i-vs-isr)
- **in** (https://plainspell.com/en/vs/in-vs-isr)
- **is** (https://plainspell.com/en/vs/is-vs-isr)
- **if** (https://plainspell.com/en/vs/if-vs-isr)

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/isr