Definition of 真っ先に (まっさきに)
まさき
                        真っ先に
まっさきに
massakini
adverb
•
                
at the very beginning, first of all, first and foremost, before anything else
Other readings:
                まっ先に【まっさきに】
                Related Kanji
| 真 | true, reality, Buddhist sect | 
| 先 | before, ahead, previous, future, precedence |