chiefly

• (UK) IPA^(key): /ˈtʃiːf.li/

• Audio (US):

  (file)

• Rhymes: -iːfli

From Middle English chefly; equivalent to chief +‎ -ly (adverbial suffix).

chiefly (comparative more chiefly, superlative most chiefly)

1. (focus) Especially or primarily; above all.

   Their relationship is chiefly professional.

   This is a term chiefly used by online gamers.

   • 1975 July 7, Ben A. Franklin, “MANDEL INQUIRY STIRS MARYLAND”, in The New York Times‎^[1]:

     But questions presisted^[sic], chiefly because of the acknowledged and continuing Federal investigation of Mr. Mandel's wealthy friends, W. Dale Hess and Harry W. Rogers 3d, who have profited from business with the state.

2. (focus) Mainly or principally; almost entirely.

• (above all): first and foremost, particularly; see also Thesaurus:above all
• (almost entirely): by and large, for the most part, largely; see also Thesaurus:mostly

From chief +‎ -ly (adjectival suffix).

chiefly (comparative chieflier, superlative chiefliest)

1. of or relating to a chief
   • 1890, James George Frazer, The Golden Bough, volume 2, page 261:

     The maintenance of a perpetual fire came to be associated with chiefly or royal dignity.