12-Letter Words Matching ____O____R__

There are 38 12-letter words that match ____O____R__. 10 are common words, such as BOUTONNIERES and ETHNOCENTRIC. A rarer one is SULFONYLUREA. In this set, E is the most frequent open letter (32 words). 3 words contain a doubled letter.

Full list 38

Common words

boutonnieresethnocentricheliocentrichydrosphereslegionnaireslithospheresphilodendronrhododendronthoroughbredtropospheresachlorhydriadorsoventral
boutonnieresethnocentricheliocentrichydrosphereslegionnaireslithospheresphilodendronrhododendronthoroughbredtropospheresachlorhydriadorsoventralglenohumeralhydrochlorichydrofluoricliriodendronmicroprogramphotoneutronphotosphericscolopendridtroposphericachlorhydricandrocentriccyclodextrindorsolateralhydrosphericlithosphericmicroamperesmicrofilariamicrospheresneurohumoralnonconcurredozonospheresphotospheresrencounteredrhizospheresscolopendrassulfonylurea

About this list

Words
38 (10 common words)
Common example
boutonnieres
Rare example
sulfonylurea
Doubled letters
3
Ending in S
11
Most frequent letter
E (32)

Questions

How many 12-letter words matching ____o____r__ are there?

38. 10 of them are common words.

What is a common example?

BOUTONNIERES is among the common words in this set.