12-Letter Words Matching _R________G_

There are 14 12-letter words that match _R________G_. 5 are common words, such as BREAKTHROUGH and BRICKLAYINGS. A rarer one is TRACKLAYINGS. In this set, I is the most frequent open letter (12 words). 5 words contain a doubled letter.

Full list 14

breakthroughbricklayingsdressmakingsprogrammingstraffickingsfrankalmoignprintmakingsprotozoologydrumbeatingsfreewritingsfrostbitingskremlinologypredischargetracklayings

About this list

Words
14 (5 common words)
Common example
breakthrough
Rare example
tracklayings
Doubled letters
5
Ending in S
9
Most frequent letter
I (12)

Questions

How many 12-letter words matching _r________g_ are there?

14. 5 of them are common words.

What is a common example?

BREAKTHROUGH is among the common words in this set.