Each of the Beatitudes in Matthew 5 start with the word
"blessed". What does it mean to say someone is "
blessed"?

The Latin word
"beati" ≈ "happy, fortunate, blessed" and is the origin of the English word
"beatitude" and the name of the "
Beatitudes". Latin has
one word as "
fortunate" for which Greek has
two separate words:
"blessed" from the Greek "happy" or "content".
"blessed" from the Greek "good words" as in "eulogy".
Observation: It is easier for a priest, pastor, etc., to wave their hands and
"bless" you than to actually make you
"happy".

In English, both words are merged as one
"blessed" and, historically, conflated with the word "
bliss" which is associated with "
joy".