13-Letter Words Matching ____A__S_____

There are 20 13-letter words that match ____A__S_____. 6 are common words, such as CONVALESCENCE and CONVALESCENTS. A rarer one is VULCANISATION. In this set, N is the most frequent open letter (18 words). 2 words contain a doubled letter.

Full list 20

convalescenceconvalescentsdissatisfyingintramuscularjuxtapositionsqueamishnessextravasatingextravasationextravascularhieracosphinxintravasationuncharismaticcephalosporindramatisationextrasystolesgalvanoscopesintravascularnonmainstreamultradistancevulcanisation

About this list

Words
20 (6 common words)
Common example
convalescence
Rare example
vulcanisation
Doubled letters
2
Ending in S
4
Most frequent letter
N (18)

Questions

How many 13-letter words matching ____a__s_____ are there?

20. 6 of them are common words.

What is a common example?

CONVALESCENCE is among the common words in this set.