13-Letter Words Matching ____O_______R

There are 18 13-letter words that match ____O_______R. 5 are common words, such as MICROCOMPUTER and PHILOSOPHIZER. A rarer one is PHYTOPLANKTER. In this set, E is the most frequent open letter (15 words). 2 words contain a doubled letter.

Full list 18

microcomputerphilosophizerphotoengraverschoolteachersubcontractorchemoreceptoreditorializerfibrovascularneuromuscularneurovascularphotocomposerphotoreceptormicrovascularnoncompetitornoncooperatorphotodetectorphotofinisherphytoplankter

About this list

Words
18 (5 common words)
Common example
microcomputer
Rare example
phytoplankter
Doubled letters
2
Ending in S
0
Most frequent letter
E (15)

Questions

How many 13-letter words matching ____o_______r are there?

18. 5 of them are common words.

What is a common example?

MICROCOMPUTER is among the common words in this set.