Part Of Speech:Noun
The Source Sentence and (Page Number):"I should've sold everything and brought the money to America a long time ago" became his mantra. (Pg.129)
Context Clues:revolution
Definition:A word or formula, as from the Veda, chanted or sung as an incantation or prayer.
Your Original Sentence: Since I've been a child my mantra has been "goal" after a goal in a soccer game.