verdaderamente
/beɾdaˌdeɾaˈmente/ · B1 · adv
truthfully
verdadera + mente = true + -ly, so truly or truthfully
Verdadero comes from verdad (truth), from Latin veritas, as in English verity. Adding -mente turns an adjective into an adverb, the way -ly does in English: verdadera + mente = truthfully.