12-Letter Words Matching ____A_____D_

There are 13 12-letter words that match ____A_____D_. 2 are common words, such as FORMALDEHYDE and MORTARBOARDS. A rarer one is SERVANTHOODS. In this set, T is the most frequent open letter (9 words). 3 words contain a doubled letter.

Full list 13

formaldehydemortarboardsacetaldehydebenzaldehydeinexactitudetryparsamidealloantibodyautoantibodycannabinoidsfantasylandspentapeptideprosauropodsservanthoods

About this list

Words
13 (2 common words)
Common example
formaldehyde
Rare example
servanthoods
Doubled letters
3
Ending in S
5
Most frequent letter
T (9)

Questions

How many 12-letter words matching ____a_____d_ are there?

13. 2 of them are common words.

What is a common example?

FORMALDEHYDE is among the common words in this set.