What does "mainline" mean?
An airline's main operating unit, as opposed to codeshares or regional subsidiaries.
Mainline
/ˈmeɪnˌlaɪn/ adj, noun, verb, slang
adj, noun, verb, slang ·Common ·High school level
Meaning at a glance
- Primary sense: An airline's main operating unit, as opposed to codeshares or regional subsidiaries.
- Grammar: mainline is listed as adj, noun, verb, slang.
- Nearest alternatives: attach, central, central thread, chief.
- Useful contrasts: alternative, branch, branch line.
- Usage evidence: At a time when mainline denominations are engaged in massive closures of small rural churches, independent charismatics are strategically helping to rechurch rural Canada.
How to use "mainline"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "mainline" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "mainline" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "mainline" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "mainline" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "mainline" is acting as adj, noun, verb, slang in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "attach" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "mainline", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 1 An airline's main operating unit, as opposed to codeshares or regional subsidiaries.
- 2 The principal route or line of a railway.
- 3 In longline fishing the central line to which the branch lines with baits are attached.
- 4 The pipeline carrying wastewater to the public drains or a septic tank.
"Many plumbers will tell you they don't go off property since that is the local water company's responsibility. Most local water companies would prefer that, if a line is snaked, it is snaked all the way to the mainline connection."
- 5 A principal vein into which a drug can be injected. slang
"I'm searching for my mainline / I said I couldn't hit it sideways"
Show 3 more definitions
- 6 The main repository for a software project, from which different versions (forks) may be split off.
- 7 Alternative form of main line. alt-of, alternative
"8. ...Qe7! is the mainline and Black unpins with Nc6-d8-e6 […]"
- 8 The general population of a prison.
Verb
- 1 To inject (a drug) directly into a vein. slang
"The patient skinpopped for 1½ years and then started to mainline heroin."
- 2 inject into the vein wordnet
- 3 To consume voraciously. broadly, informal, transitive
"Last month, she lamented that her busy campaign schedule had kept her from mainlining Amazon’s new “Rings of Power” series."
- 4 To integrate (code, etc.) into the main repository for a software project, rather than separate forks. transitive
- 5 To include (a prisoner) in the general population of a prison. transitive
Adjective
- 1 Normal, principal or standard. not-comparable
"At a time when mainline denominations are engaged in massive closures of small rural churches, independent charismatics are strategically helping to rechurch rural Canada."
- 2 Of or pertaining to the principal route or line of a railway. not-comparable
- 3 Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one. not-comparable
- 4 Of a sequence of opening moves: being part of a main line ("a standard sequence of opening moves considered to be best play"). not-comparable
"After 3 e5 the Czech Benoni Defense is created. Unlike the mainline 3 e6, which aims for tactical counterplay in the center, Black aims for solidity there. He will choose later what flank to attack on."
Synonyms
All synonymsAntonyms
Example
"At a time when mainline denominations are engaged in massive closures of small rural churches, independent charismatics are strategically helping to rechurch rural Canada."
Common questions
What is a synonym for "mainline"?
Common synonyms include: attach, central, central thread, chief, connect, conventional.
How do you use "mainline" in a sentence?
At a time when mainline denominations are engaged in massive closures of small rural churches, independent charismatics are strategically helping to rechurch rural Canada.
How do you pronounce "mainline"?
Pronounced /ˈmeɪnˌlaɪn/.
Etymology
From main + line.