意気込む

いきごむ

to be enthusiastic (about); to be eager (to do); to be keen; to be intent (on)

JLPT N1 common word Also written 意気ごむ

Meaning

v5mvi
to be enthusiastic (about); to be eager (to do); to be keen; to be intent (on); to be determined

Example sentences

初めから意気込みすぎると、途中で息切れするぞ。

You have to pace yourself or you'll choke halfway through.
せっかく、英語で注文しようと意気込んで入ったのに、日本語で「いらっしゃいませ」って言われた。あれ？って感じ。

After I got all worked up about ordering in English, I walked in the store and they greeted me with "Irasshaimase!" I felt, like, "What the ...?"