# Ios

/ˈaɪoʊs/ (US)

Source: https://englishreference.com/word/ios
Updated: 2026-08-15

## Senses

### 1. Apple mobile operating system

noun · CEFR B2 · Technical

Stands for iPhone Operating System. This is the software that makes your iPhone or iPad work.

For teachers: Abbreviation for iPhone Operating System. The proprietary mobile operating system developed by Apple Inc. for its handheld devices.

- I need to update my phone to the latest version of iOS to use this app.
- The developer noted that the application's performance improved significantly after the latest iOS kernel update was deployed.

Usage: Usually written in lowercase 'i' followed by uppercase 'OS'.

Teaching tip: While originally used for both iPhone and iPad, Apple now uses 'iPadOS' for tablets, though many people still use 'iOS' as a general term for both.

### 2. Greek island

noun · CEFR C1 · Formal

A small Greek island in the Aegean Sea, known for its beautiful beaches and nightlife.

For teachers: A specific island within the Cyclades group in the Aegean Sea, Greece.

- We took a ferry from Santorini to spend a few days on the island of Ios.
- Archaeological excavations on Ios have revealed significant settlements dating back to the early Cycladic period.

Usage: Always capitalized as a proper noun.

## Examples

- I need to update my iOS to get the latest features.
- The developer spent weeks ensuring the new mobile application was fully compatible with the latest version of iOS.
- While Android offers greater customisation for power users, iOS is often praised for its consistent user interface and the tight integration between its hardware and software components.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.