Definition of "in earnest" []

• Sincere; determined; truthful. (adjective)
• Seriously; sincerely, in a significant manner; with considerable commitment, determination, or effect. (adverb)

Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License

• "Civil wars soon began in earnest when Perdiccas had Meleager murdered in the sanctuary of a temple where he had sought refuge."
• "Her rise to mega-stardom began in earnest in 1995, when MTV hired her to co-host its new dating show, Singled Out."
• "(As a matter of curiosity we may mention that there have been people who took in earnest the interpretation of prosa as = pro sã, i.e. pro sequentia.)"