4-Letter Words Matching B_O_

There are 17 4-letter words that match B_O_. 16 are common words, such as BIOS and BLOB. A rarer one is BROO. In this set, O is the most frequent open letter (8 words). 8 words contain a doubled letter.

Full list 17

biosblobblocblogblotblowbookboomboonboorboosbootbrosbrowbuoybrooboob

About this list

Words
17 (16 common words)
Common example
bios
Rare example
broo
Doubled letters
8
Ending in S
3
Most frequent letter
O (8)

Questions

How many 4-letter words matching b_o_ are there?

17. 16 of them are common words.

What is a common example?

BIOS is among the common words in this set.