まっさきにMeaningsAdverb1. at the very beginning; first of all; first and foremost; before anything elseOther spellings真まっ先さきに39%まっ先さきに4%Kanji in other spellings真truth先before (timewise)Composed ofまっさきthe head; the foremost; beginning; the very frontNounにat; in; on; to; toward; into; for; in order to; because of; with; …Particle