1 - An airline's main operating unit, as opposed to codeshares or regional subsidiaries.
2 - The main repository for a software project, from which different versions (forks) may be split off.
1 - To inject (a drug) directly into a vein.
2 - To integrate (code, etc.) into the main repository for a software project, rather than separate forks.
1 - Normal, principal or standard.
2 - Of or pertaining to the principal route or line of a railway.
3 - Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one.





