Mainline

Origin

• main + line

Adjective

1. normal, principal or standard.
2. (rail transport) Of or pertaining to the principal route or line of a railway
3. (rail transport) Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one.

Synonyms

• (normal, principal or standard) mainstream

Full definition of mainline

Verb

1. To inject (a drug) directly into a vein.

Derived terms

• mainliner
• mainlining