15-Letter Words Matching ____HA_________

There are 12 15-letter words that match ____HA_________. 3 are common words, such as FOOLHARDINESSES and OPHTHALMOLOGIES. A rarer one is TEACHABLENESSES. In this set, L is the most frequent open letter (11 words). 3 words contain a doubled letter.

Full list 12

foolhardinessesophthalmologiesophthalmologistlymphadenopathymerchantabilitymischaracterizeophthalmoscopeslaughablenesseslymphadenitiseslymphangiogramsophthalmoscopicteachablenesses

About this list

Words
12 (3 common words)
Common example
foolhardinesses
Rare example
teachablenesses
Doubled letters
3
Ending in S
7
Most frequent letter
L (11)

Questions

How many 15-letter words matching ____ha_________ are there?

12. 3 of them are common words.

What is a common example?

FOOLHARDINESSES is among the common words in this set.