Definition of "main"

adjective:
- Great in size or degree; vast; strong; powerful; important.
  
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- Principal or chief in size or extent; largest; consisting of the largest part; most important by reason or size or strength.
  
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- Belonging to or connected with the principal mast in a vessel.
  
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- Big; angry.
  
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adverb:
- Very; very much; greatly; mightily; extremely; exceedingly.
  
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noun:
- That which is chief or principal; the chief or main portion; the gross; the bulk; the greater part.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License