To bless means something a little bit like to give a gift, but this gift is often very intangible. My project manager can "bless" my proposal for a new feature, for example, and that means declaring his approval, commitment, or support for it. So it is something that can be given to God, similar to honor, praise, or worship.

The Hebrew stem "shabah" means "praise", so the more correct translation would be "Praise be". Blessing seems to be a later Christian concept. The old Jewish G-d wasn't much into blessings, more into mass murder:)

It helps to think of older terms and how they relate to more-common modern terms.

"Benediction" is a synonym for one sense of "blessing" — the sense that means "to speak good upon" (bene- and -dict).

Conversely, a synonym for one sense of "curse" is "malediction", which is the opposite of "benediction": "to speak bad/evil upon" (mal- and -dict).