13-Letter Words Matching ________OP___

There are 33 13-letter words that match ________OP___. 7 are common words, such as ACETAMINOPHEN and ARCHBISHOPRIC. A rarer one is THERMOTROPISM. In this set, I is the most frequent open letter (32 words). 2 words contain a doubled letter.

Full list 33

Common words

acetaminophenarchbishopriccolonoscopiesmisanthropiesmisanthropistpsychotropicstriceratopsesapogeotropismarthroscopiesdeuteranopiasdiageotropismfluoroscopies
acetaminophenarchbishopriccolonoscopiesmisanthropiesmisanthropistpsychotropicstriceratopsesapogeotropismarthroscopiesdeuteranopiasdiageotropismfluoroscopiesgonadotropinsheterotrophiclaparoscopieslycanthropiesstereoscopiesstereotropismstormtroopersthigmotropismfluoroscopingfluoroscopistgastroscopiesgastroscopistgonadotrophicgonadotrophinlaparoscopistmisdevelopingnincompooperyretinoscopiessomatotrophinsomatotropinsthermotropism

About this list

Words
33 (7 common words)
Common example
acetaminophen
Rare example
thermotropism
Doubled letters
2
Ending in S
15
Most frequent letter
I (32)

Questions

How many 13-letter words matching ________op___ are there?

33. 7 of them are common words.

What is a common example?

ACETAMINOPHEN is among the common words in this set.