13-Letter Words Matching A___________T

There are 20 13-letter words that match A___________T. 10 are common words, such as ACCOMPANIMENT and ACUPUNCTURIST. A rarer one is ANTISOCIALIST. In this set, I is the most frequent open letter (19 words). 6 words contain a doubled letter.

Full list 20

accompanimentacupuncturistadvertisementadvertizementagriculturistanticoagulantanticommunistapportionmentarchaeologistascertainmentabortifacientadmeasurementannexationistantiterroristaquaculturistantidesiccantantiformalistantimechanistantimodernistantisocialist

About this list

Words
20 (10 common words)
Common example
accompaniment
Rare example
antisocialist
Doubled letters
6
Ending in S
0
Most frequent letter
I (19)

Questions

How many 13-letter words matching a___________t are there?

20. 10 of them are common words.

What is a common example?

ACCOMPANIMENT is among the common words in this set.