mainly

UK: /ˈmeɪnli/ US: (mān′lē)

WordReference Random House Unabridged Dictionary of American English © 2025

main•ly  (mān′lē), adv. 

1. chiefly;
   principally;
   for the most part;
   in the main;
   to the greatest extent:
   Our success was due mainly to your efforts. The audience consisted mainly of students.
2. [Obs.] greatly;
   mightily;
   abundantly.

• Middle English maynliche, maynly. See main¹, -ly 1225–75

Collins Concise English Dictionary © HarperCollins Publishers::

mainly / ˈmeɪnlɪ/ adverb

1. for the most part; to the greatest extent; principally

WordReference Random House Learner's Dictionary of American English © 2025

main¹ /meɪn/   adj. [before a noun]

1. chief in size, extent, or importance:
   He had the main part in a play.
2. Grammar (in a sentence) of or relating to the clause that can stand by itself;
   independent:
   In the sentence I'll see you when I get home, the main clause is I'll see you. 

n. [countable]

3. Civil Engineering a principal pipe in a system used to carry and send water, gas, etc.

Idioms

4. in the main, most importantly:
   In the main, she has proposed a very good plan.
5. with might and main, with strength or force.

main•ly, adv. 

: He got rich mainly from government contracts.

WordReference Random House Unabridged Dictionary of American English © 2025

main¹  (mān), adj. 

1. chief in size, extent, or importance;
   principal;
   leading:
   the company's main office; the main features of a plan.
2. sheer;
   utmost, as strength or force:
   to lift a stone
   by main force.
3. of or pertaining to a broad expanse:
   main sea.
4. Grammar syntactically independent;
   capable of use in isolation. Cf. dependent (def. 4), independent (def. 14), main clause. 
5. [Naut.]
   • Nautical of or pertaining to a mainmast.
   • Nautical noting or pertaining to a sail, yard, boom, etc., or to any rigging belonging to a mainmast.
   • Nautical noting any stay running aft and upward to the head of a mainmast:
     main topmast stay.
6. [Obs.]
   • having or exerting great strength or force;
     mighty.
   • having momentous or important results;
     significant.

n. 

7. Civil Engineering a principal pipe or duct in a system used to distribute water, gas, etc.
8. physical strength, power, or force:
   to struggle with might and main.
9. the chief or principal part or point:
   The main of their investments was lost during the war.
10. [Literary.] the open ocean;
    high sea:
    the bounding main.
11. the mainland.
12. Idioms in the main, for the most part;
    chiefly:
    In the main, the novel was dull reading.

adv. 

13. Dialect Terms [South Midland U.S.] (chiefly Appalachian). very;
    exceedingly:
    The dogs treed a main big coon.

v.i., v.t. 

14. Slang Terms mainline.

• Old Norse megenn, megn strong, partly independent use of Old English mægen (noun, nominal) taken as an adjective, adjectival in compounds, as in mægen-weorc, literally, work of might
• bef. 900; (noun, nominal) Middle English meyn, mayn strength, power, Old English mægen, cognate with Old Norse megin(n), megn strength; (adjective, adjectival) Middle English mayn, partly

Synonyms

• 1. cardinal, prime, paramount, primary, capital.
• 2. pure, direct.
• 7. conduit.
• 8. might.

Antonyms

• 1. secondary, least.
• 8. weakness.

main²  (mān), n. 

1. a cockfighting match.

• 1560–70; perh. special use of main¹; compare main chance

Main  (mān; Ger. mīn), n. 

1. Place Names a river in central and W Germany, flowing W from the Bohemian Forest in N Bavaria into the Rhine at Mainz. 305 mi. (490 km) long.