Which word means to make someone blissfully happy?

To make someone blissfully happy is aptly described by the word "beatify." This term originates from a Latin root meaning to make happy or blissful, and is often associated with the process of beatification in a religious context, where an individual is declared blessed and thus can evoke joy and positivity in others.

In contrast, the other options do not convey the same meaning. "Attenuate" refers to making something weaker or less intense, which has no connection to happiness. "Calumniate" means to make false and defamatory statements about someone, which is a negative and harmful action. "Assay" involves testing or analyzing, usually in a scientific context, and does not pertain to emotions or happiness. Therefore, "beatify" is clearly the term that signifies bringing about blissful happiness.