Definition of "mainly"

mainly

/ˈmeɪnli/

adverb
not comparable
1. Chiefly; for the most part.
  Quotations
  She had Lord James' collar in one big fist and she pounded the table with the other and talked a blue streak. Nobody could make out plain what she said, for she was mainly jabbering Swede lingo, but there was English enough, of a kind, to give us some idee.
  1913, Joseph C. Lincoln, chapter 12, in Mr. Pratt's Patients
2. (obsolete) Forcefully, vigorously.
  Quotations
  Such breadth of ſhoulders as might mainely beareOlde Atlas burthen, […]
  c. 1587–1588, [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire, London: Scolar Press, 1973, (please specify the page)
  Mainly they all attonce vpon him laid, / And sore beset on euery side around […]
  1590, Edmund Spenser, “Book III, Canto I”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie
3. (obsolete) Of the production of a sound: loudly, powerfully.
  Quotations
  But in the end, mainly crying out, he fell to raling and wringing his master, upbraiding him that he was not a true Philosopher […].
  1603, Michel de Montaigne, chapter 31, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […]
4. (obsolete) To a great degree; very much.