MAINLINE
mainline
(verb) inject into the vein; “She is mainlining heroin”
Source: WordNet® 3.1
Etymology
Adjective
mainline (not comparable)
Normal, principal or standard.
(rail transport) Of or pertaining to the principal route or line of a railway.
(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
Verb
mainline (third-person singular simple present mainlines, present participle mainlining, simple past and past participle mainlined)
To inject (a drug) directly into a vein.
Synonym: main
(computing, transitive) To integrate (code, etc.) into the main repository for a software project, rather than separate forks.
Noun
mainline (plural mainlines)
(aviation) An airline's main operating unit, as opposed to codeshares or regional subsidiaries.
(computing) The main repository for a software project, from which different versions (forks) may be split off.
Source: Wiktionary