13-Letter Words Matching __________A_S

There are 104 13-letter words that match __________A_S. 38 are common words, such as ANTIMACASSARS and ANTIMALARIALS. A rarer one is ULTRARADICALS. In this set, I is the most frequent open letter (91 words). 21 words contain a doubled letter.

Full list 104

Common words

antimacassarsantimalarialsbacchanaliansbicentennialscaravanseraiscommissariatscompanionwaysconfessionalscosmopolitansdifferentialsfountainheadsheterosexuals
antimacassarsantimalarialsbacchanaliansbicentennialscaravanseraiscommissariatscompanionwaysconfessionalscosmopolitansdifferentialsfountainheadsheterosexualshumanitariansinstrumentalsintellectualsinvitationalskleptomaniacsmegalomaniacsnonagenariansnonspiritualsnymphomaniacsobstetriciansoctogenarianspediatriciansprocessionalsprofessionalsproportionalsquarterfinalssalutatorianssexagenariansstatisticiansstraightawayssuperhighwayssupernaturalstheoreticianstotalitariansvaudevilliansveterinariansagrochemicalsbacteriostatschromatogramsdialecticiansequalitariansgeometriciansgeriatricianshymenopteranshypotheticalslepidopteransmajoritariansmelancholiacsnecrophiliacsplanetesimalsprehistoriansproboscideansyellowthroatsaestheticiansagrichemicalsantediluviansanticlericalsanticolonialsbibliomaniacsbimillennialsbiometricianscoprophiliacsdibenzofuransfutilitarianshemorrhoidalshereditarianshexobarbitalshyperarousalsinterglacialsinterstadialsmetropolitansmicrocrystalsmicrohabitatsmicroprogramsmisappraisalsnonessentialsnonlibrariansnonnumericalsnonphysiciansnonuniversalsonomasticiansonychophoranspogonophoranspostdiluvianspreceptorialspresbyterialsproboscidiansprocathedralsprofessoriatsproteoglycansquinquennialssecobarbitalsspermatozoanssublibrarianssubprincipalssuperspecialssupplementalsthalassocratstrichopteransturbellariansultraliberalsultraradicals

About this list

Words
104 (38 common words)
Common example
antimacassars
Rare example
ultraradicals
Doubled letters
21
Ending in S
104
Most frequent letter
I (91)

Questions

How many 13-letter words matching __________a_s are there?

104. 38 of them are common words.

What is a common example?

ANTIMACASSARS is among the common words in this set.