They keep pouring down, requiring some kind of definition(s). Continuing to read in First Peter, and could not let "bless" just get passed over. It appears so often in our everyday speech, and of course, it's all over the Bible. At first, trying to find a definition was like putting toothpaste back in the tube – in other words, it wasn't easy.
Looking up definitions online was of some help, but the problem there were the number of definitions. Basically, it boils down to "gaining God's favor" or being honored or special. When you are blessed, you are more holy. There was even one definition that linked the english "bless" with a germanic "blessing" (can't type german or old saxon) that was related to the spilling of blood.[more]
Finally, they tied the old germanic "bless" back to the Old Testament where blood had to be spilled to make the offering "special." Interesting, that the further back you go, the more meaning words sometime have. Think about that, the thing that made the offering special was the spilling of blood. And that is just what Peter is talking about here in chapter 3, where he talks about "Christ died for our sins…"
Peter's challange starts in verse 9 where he wants us to "bless rather than curse (insult)" just because we have been blessed. It continues where he urges us to "sanctify Christ (set Him apart) as our leader." Interesting that he uses the term "set apart" – it's kind of like there can only be one leader.
There is more here, so don't go away. This chapter is full of challenges and can't be glossed over.