# basis

/ˈbeɪsəs/ (US) · /bˈeɪsɪs/ (UK)

Source: https://englishreference.com/word/basis
Updated: 2026-06-19

## Senses

### 1. foundation or reason

noun · CEFR B1

the main reason or idea that something is built on.

For teachers: the underlying support or justification for an idea, argument, or system.

- The report provided a solid basis for the company's new strategy.
- The scientific community accepted the hypothesis as a basis for further research into the long-term effects of climate change.

Usage: Often used with the preposition 'for'.

### 2. regular frequency

noun · CEFR B1

the way or how often something happens.

For teachers: a regular pattern or frequency of occurrence.

- We meet on a regular basis to discuss our progress.
- The security software updates on a daily basis to protect the network against emerging digital threats.

Usage: Typically used in the construction 'on a [adjective] basis'.

### 3. investment cost

noun · CEFR C1 · Technical

the total amount of money spent on an investment, including fees.

For teachers: the original value of an asset for tax purposes, usually the purchase price adjusted for commissions and other expenses.

- You need to calculate your tax basis before selling the property.
- The accountant adjusted the cost basis of the shares to account for the recent stock split and brokerage fees.

Teaching tip: This sense is specific to tax and accounting contexts; general learners should focus on the 'foundation' meaning.

### 4. vector space

noun · CEFR C2 · Technical

a set of basic vectors used to describe a space in math.

For teachers: a set of linearly independent vectors that span a given vector space.

- The teacher explained how to find the basis of a three-dimensional space.
- In linear algebra, any vector in the space can be represented as a unique linear combination of the basis elements.

## Examples

- We meet on a weekly basis to discuss our progress.
- The company hires new staff on a temporary basis before offering them a permanent contract.
- Scientific theories must be evaluated on the basis of empirical evidence rather than personal intuition or anecdotal reports.

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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.