Enthusiasm or eagerness; a strong, energetic determination to tackle something.
新入社員は皆、意気込みを持って仕事を始めた。
All the new employees started work with enthusiasm.
大会に向けての選手の意気込みが伝わってきた。
You could sense the players' determination heading into the tournament.
代表としての意気込みをスピーチで述べた。
He expressed his determination as a representative in his speech.