Marina,
I have another small group I created to test Groups.io.
The group description in Directory has the same problem: same word in bold.
That's odd. I found that group in the directory and I don't see any bold-faced word. In fact, it doesn't look like the directory shows any formatting that the group Description might have.
Or maybe you've gone on to other testing by now, as that group's Description looks very short (one sentence) and no formatting also on the group's home page:
If you're still seeing one of those words in bold, maybe there's a plug-in or other software affecting what your browser is showing you. Otherwise I don't know how to explain it.
Shal
Shal Farley