15-Letter Words Matching ________I____M_

There are 18 15-letter words that match ________I____M_. 7 are common words, such as ANTIQUARIANISMS and DISEQUILIBRIUMS. A rarer one is TERRITORIALISMS. In this set, S is the most frequent open letter (18 words). 3 words contain a doubled letter.

Full list 18

antiquarianismsdisequilibriumsegalitarianismsexistentialismsneocolonialismsobstructionismsutilitarianismsabstractionismsassociationismslibertarianismsmillenarianismsechocardiogramslymphangiogramsmultiracialismsnonequilibriumsphotoperiodismsrestrictionismsterritorialisms

About this list

Words
18 (7 common words)
Common example
antiquarianisms
Rare example
territorialisms
Doubled letters
3
Ending in S
18
Most frequent letter
S (18)

Questions

How many 15-letter words matching ________i____m_ are there?

18. 7 of them are common words.

What is a common example?

ANTIQUARIANISMS is among the common words in this set.