15-Letter Words Matching ____________A_S

There are 26 15-letter words that match ____________A_S. 6 are common words, such as CONSTITUTIONALS and DISCIPLINARIANS. A rarer one is UNPROFESSIONALS. In this set, I is the most frequent open letter (25 words). 4 words contain a doubled letter.

Full list 26

Common words

constitutionalsdisciplinarianslatitudinarianspharmaceuticalsseptuagenariansvaletudinarianseconometricianssesquipedaliansbiogeochemicalsechocardiogramselectromyogramsethnohistorians
constitutionalsdisciplinarianslatitudinarianspharmaceuticalsseptuagenariansvaletudinarianseconometricianssesquipedaliansbiogeochemicalsechocardiogramselectromyogramsethnohistoriansichthyosaurianslymphangiogramsnonutilitarianspredestinarianspremillenariansprotohistorianspsychochemicalsquincentennialssabermetricianssemicentennialssolitudinarianssubproletariatsuniformitariansunprofessionals

About this list

Words
26 (6 common words)
Common example
constitutionals
Rare example
unprofessionals
Doubled letters
4
Ending in S
26
Most frequent letter
I (25)

Questions

How many 15-letter words matching ____________a_s are there?

26. 6 of them are common words.

What is a common example?

CONSTITUTIONALS is among the common words in this set.