13-Letter Words Matching ___R_____O___

There are 43 13-letter words that match ___R_____O___. 7 are common words, such as BOARDINGHOUSE and NONRECIPROCAL. A rarer one is ULTRARATIONAL. In this set, O is the most frequent open letter (34 words). 8 words contain a doubled letter.

Full list 43

Common words

boardinghousenonreciprocaloverdevelopedoveremotionalpharmacopoeiasupranationalthoroughgoingandrosteronescorrelationaldepressomotorhydrocarbonicmacroeconomic
boardinghousenonreciprocaloverdevelopedoveremotionalpharmacopoeiasupranationalthoroughgoingandrosteronescorrelationaldepressomotorhydrocarbonicmacroeconomicmicroeconomicpharmacologicspermatozoidsspirochetosisthoroughwortsuntraditionalaggregationalattributionalbourguignonneextrasystolesfibrosarcomashydrocolloidshydroquinonesintrapersonalmicrobiologicmicrocosmosesneuroanatomicneurofibromasneurohormonalneurohormonesovercautionedoverwithholdsplerocercoidsreprovisionedspermatogoniaspermatozoansspirochetosessuprarationaltetrapyrrolesultraorthodoxultrarational

About this list

Words
43 (7 common words)
Common example
boardinghouse
Rare example
ultrarational
Doubled letters
8
Ending in S
16
Most frequent letter
O (34)

Questions

How many 13-letter words matching ___r_____o___ are there?

43. 7 of them are common words.

What is a common example?

BOARDINGHOUSE is among the common words in this set.