Chiefly

Adverb

 * 1)  especially or primarily; above all
 * 2)  mainly or principally; almost entirely

Adjective

 * of, or relating to a chief

Thesaurus
a fortiori, ab initio, ab ovo, aborigine, above all, all in all, all the more, all things considered, almost entirely, altogether, approximately, as a rule, as a whole, as an approximation, as per usual, as things go, as usual, at first, at large, at the start, before everything, broadly, broadly speaking, by and large, commonly, customarily, dominantly, effectually, especially, essentially, even, ever so, first, first and foremost, first of all, first thing, firstly, from the beginning, generally, generally speaking, habitually, in chief, in general, in particular, in the beginning, in the main, indeed, initially, largely, mainly, more than ever, most often, mostly, naturally, never so, no end, normally, normatively, on balance, on the whole, ordinarily, originally, overall, particularly, peculiarly, predominantly, prescriptively, prevailingly, primarily, primo, principally, regularly, roughly, roughly speaking, routinely, speaking generally, still more, substantially, to be expected, usually, virtually, yea

Adverb

 * Arabic: (ğāliban)
 * Armenian: գլխավորապես, հատկապես
 * Bulgarian: главно, предимно
 * Chinese: 主要 (zhǔyào)
 * Dutch:
 * Esperanto:
 * Finnish:, suurimmaksi osaksi, , etupäässä, pääasiallisesti, pitkälti
 * French:
 * German:
 * Hungarian:


 * Italian:
 * Japanese: おもに (omoni)
 * Korean: 주로 (juro)
 * Polish:
 * Portuguese:
 * Russian: more literary and official, в основном (v osnovnóm) (mainly);  (especially); первоочерёдно rare, literary, в   (primarily, first and foremost)
 * Spanish:
 * Swedish: