peripheral
/pəˈrɪf.ər.əl/Relating to the outer edge or boundary of something, rather than the center. When used to describe an issue or idea, it means it is not the main focus and is of lesser importance.
- Her role in the project was peripheral — she only attended two meetings.
- The report focuses on the core issue, not peripheral concerns.
- Small villages in the peripheral regions lacked clean water access.
A piece of hardware that is connected to a computer but is not the main computer itself. Common examples are a printer, mouse, keyboard, or external hard drive.
- She bought a wireless keyboard and other peripherals for her desk.
- The IT team checked whether all peripherals were properly connected.
- A scanner is a useful peripheral for any home office.
Adinary Nuance
Peripheral, marginal, tangential, and secondary all suggest something is not the main thing — but they differ in important ways. Peripheral is the most spatially neutral: it pictures something sitting at the edge of a circle, not necessarily unimportant, just not at the centre. Marginal is stronger and often dismissive — it implies something barely qualifies or barely matters. Tangential is more precise: it describes something that touches the main topic briefly but then moves in a different direction entirely, making it a favourite in academic and IELTS writing ("that point is tangential to the argument"). Secondary is hierarchical — it means "ranked second in importance" — whereas peripheral says nothing about rank; it is simply off-centre. In an IELTS essay, reaching for "peripheral" instead of "not very important" will immediately raise your lexical resource score.
In other languages
- Vietnamese
- Ngoại vi / không trọng tâm
- Spanish
- Periférico
- Chinese
- 外围的
- Japanese
- 周辺の
- Korean
- 주변의
Etymology
From Latin "peripheria" and Greek "periphereia," meaning "carrying around" or "circumference," built from "peri-" (around) and "pherein" (to carry). It entered English in the mid-19th century, first in anatomical and geometric contexts, later extending to computing and general use.
Common phrases
Synonyms
Related words
Frequently asked questions
- Is 'peripheral' a formal word?
- Yes, it leans formal and is common in academic writing, IELTS essays, and professional reports. In casual speech, people usually say 'not important' or 'not the main point' instead.
- What is the difference between 'peripheral' and 'marginal'?
- 'Peripheral' neutrally means 'at the edge or not central,' while 'marginal' often carries a dismissive tone — implying something barely counts or barely matters. You can call an issue 'peripheral' without being harsh; calling it 'marginal' sounds more critical.
- Can 'peripheral' be used as a noun?
- Yes. In computing, 'a peripheral' (or 'peripheral device') means any external hardware connected to a computer — such as a printer, mouse, or USB drive. It is very commonly used in this noun form in tech contexts.
- How do I use 'peripheral' in an IELTS essay?
- Use it to show that an issue or argument is not the main concern — for example: 'While cost is a peripheral concern, the core problem remains one of public policy.' This signals strong vocabulary range to IELTS examiners.