EARNEST

[adjective] - serious or determined, esp. too serious and unable to find your own actions amusingAt school he was very earnest but he's more relaxed now.She made an earnest attempt to convert me to her point of view.These fanatics are in deadly earnest (= completely serious) when they say they want to destroy all forms of government.If something is done in earnest, it is done with seriousness and attention.After sharpening all his pencils and making a cup of tea, he started drawing in earnest.When something begins in earnest, it has already started but is now being done in a serious and complete way.The election campaign has begun in earnest, with both parties severely criticizing the other.