The phrase "was in earnest" means to be sincere, committed or serious about a particular matter or task. There are several synonyms for this phrase that can be used to convey the same meaning in different ways, such as genuine, determined, resolute, dedicated, honest, fervent, enthusiastic, passionate, zealous, and sincere. These words demonstrate a deep level of commitment and sincerity in a person's actions or beliefs, and are often used to describe individuals who are striving towards achieving their goals with great passion and persistence. Whether it's in personal or professional settings, using synonyms for "was in earnest" can add depth and nuance to one's verbal and written communication.