# mainline

/ˈmeɪnˌɫaɪn/ (US) · /mˈeɪnlaɪn/ (UK) · CEFR C2 · Verb

Source: https://englishreference.com/word/mainline
Updated: 2026-05-09

## Definition

to inject a drug directly into a vein. In a more general way, it can mean to experience or consume something very quickly and intensely.

For teachers: to inject a drug intravenously; by extension, to consume or integrate something in a direct, concentrated, or unfiltered manner. Often used metaphorically in computing to describe merging code into a primary development branch.

## Examples

- He was caught trying to mainline heroin in the alley.
- The developer worked all weekend to mainline the new security patches into the software's core repository.
- Fans of the series tend to mainline every new season in a single sitting, consuming the entire narrative arc before the spoilers can reach social media.

## Usage notes

- The verb is transitive and typically takes a direct object representing the substance or content being consumed.

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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.