WordNet

for the most part; "he is mainly interested in butterflies" (同)principally, primarily, mainly, in the main
of the field of academic study in which one concentrates or specializes; "his major field was mathematics"
a commissioned military officer in the United States Army or Air Force or Marines; below lieutenant colonel and above captain
a university student who is studying a particular field as the principal subject; "she is a linguistics major"
the principal field of study of a student at a university; "her major is linguistics"
greater in number or size or amount; "a major portion (a majority) of the population"; "Ursa Major"; "a major portion of the winnings"
greater in scope or effect; "a major contribution"; "a major improvement"; "a major break with tradition"; "a major misunderstanding"
have as ones principal field of study; "She is majoring in linguistics"
of a scale or mode; "major scales"; "the key of D major"
of full legal age
of greater importance or stature or rank; "a major artist"; "a major role"; "major highways"
of greater seriousness or danger; "a major earthquake"; "a major hurricane"; "a major illness"
of the elder of two boys with the same family name; "Jones major"
of force; of the greatest possible intensity; "by main strength"
a principal pipe in a system that distributes water or gas or electricity or that collects sewage
any very large body of (salt) water (同)briny
of primary import; "this is primarily a question of economics"; "it was in the first place a local matter" (同)in_the_first_place
much greater in number or influence; "the patients are predominantly indigenous" (同)preponderantly
most important element; "the chief aim of living"; "the main doors were of solid glass"; "the principal rivers of America"; "the principal example"; "policemen were primary targets"; "the master bedroom"; "a master switch" (同)main, primary, principal, master

PrepTutorEJDIC

『主として』,おもに(mainly) / まず第一に,とりわけ
『大きい』(『多い』)『ほうの』,いっそう重要な / (音階が)長調の,長音階の / 《英》《昔の学校で同姓または兄弟生徒を区別するために姓の後につけて》年長の,兄の / 《しばしばM-》陸軍(空軍)少佐 / 《米》専攻科目;専攻学生 / 《the majors》《米》=major leagues / (科目を)専攻する《+『in』+『名』》
《名詞の前にのみ用いて》『おもな,主要な』 / 〈C〉《通例複数形で》(水道・ガスなどの)本管;主電線;(鉄道の)本線,幹線 / 〈U〉《the~》《詩》大海,大海原(おおうなばら)
『第一に』,主として,おもに(chiefly) / 最初に(originally)
たいていは,主として
優勢な;(…に対して)有力な《+『over』+『名』》 / 最も(ひんぱんに)目につく
(組織・集団の)『長』;長官,局(部,課)長;(部族の)長 / 『最高位の』,長である / 『最も重要な』,おもな(most important; main)