15-Letter Words Matching I____________A_

There are 18 15-letter words that match I____________A_. 3 are common words, such as IMPROVISATIONAL and INCONSEQUENTIAL. A rarer one is INVESTIGATIONAL. 2 words contain a doubled letter.

Full list 18

improvisationalinconsequentialintelligentsiasimprovisatorialinfrastructuralinterrogationalintrapreneurialisoperimetricalinterbehavioralinterdivisionalinterindividualinterparoxysmalinterperceptualinterphalangealinterprovincialintraperitonealintrospectionalinvestigational

About this list

Words
18 (3 common words)
Common example
improvisational
Rare example
investigational
Doubled letters
2
Ending in S
1

Questions

How many 15-letter words matching i____________a_ are there?

18. 3 of them are common words.

What is a common example?

IMPROVISATIONAL is among the common words in this set.