1. in earnest - Adjective
2. in earnest - Adverb
in a serious manner
Source: WordNetWe are always on stage, even when we are stabbed in earnest at the end. Georg Büchner
At seventy-seven it is time to be in earnest. Samuel Johnson
The squirrel that you kill in jest, dies in earnest. Henry David Thoreau
When one dog barks for nothing, all other dogs bark in earnest. Japanese Proverb
Said in sport, meant in earnest. German Proverb
We knock in jest, and it is opened in earnest. German Proverb