Emily Dickinson Lexicon

MAIN, a. [Sax. mægn, strength, force, power, from magan, to be able or strong, that is, to strain or stretch, Eng. may, might. If g is radical in the L. magnus, this may be of the same family; Goth. mickels; Eng. much.]

1. Principal; chief; that which has most power in producing an effect, or which is mostly regarded in prospect; as, the main branch or tributary stream of a river; the main timbers of an edifice; a main design; a main object. Our main interest is to be as happy as we can, and as long as possible. Tillotson.
2. Mighty; vast; as, the main abyss. Milton.
3. Important; powerful. This young prince, with a train of young noblemen and gentlemen, not with any main army, came over to take possession of his patrimony. Davies.