来自古英语maegen,能力，力量，强壮，来自PIE*magh,使有能力，赋予力量，词源同machine,magic,might.引申词义主要的，最重要的。原词义见短语might and main,尽全力。拼写比较dainty,fain,rain.
main: [OE] Main goes back to prehistoric Germanic *mag- ‘be able, have power’ (source also of English may and might, and distantly related to machine). From it was descended Old English mægen ‘strength’. This now survives as a noun only in the expression with might and main, but it was also used attributively in Old English to mean ‘of large size, great’, and by the 13th century (helped along partly by the related Old Norse megenn or megn ‘strong’) it was being used as an adjective in its own right. At first it still meant just ‘large’, but by the 15th century its modern sense ‘chief’ had evolved. => may, might
Old English mægen (n.) "power, bodily strength, force, efficacy," from Proto-Germanic *maginam "power," suffixed form of PIE root *magh- (1) "be able, have power" (see may (v.)). Original sense preserved in phrase with might and main. Meaning "principal channel in a utility system" is first recorded 1727 in main drain. Used since 1540s for "continuous stretch of land or water;" in nautical jargon used loosely for "the ocean," but in Spanish Main the word is short for mainland and refers to the coast between Panama and Orinoco (as contrasted to the islands of the West Indies).
early 13c., "large, bulky, strong," from Old English mægen- "power, strength, force," used in compounds (such as mægensibb "great love," mægenbyrðen "heavy burden;" see main (n.)), probably also from or influenced by Old Norse megenn (adj.) "strong, powerful." Sense of "chief" is c. 1400. Main course in the meal sense attested from 1829. Main man "favorite male friend; hero" is from 1967, U.S. black slang.
1. The study links the main living area to the kitchen.
2. They used a lorry to ram the main gate.
3. Premature birth is the main cause of perinatal mortality.
4. On South Main Street, a huge brick building looms into view.
5. The main characteristic of the strike has been its longevity.