10-Letter Words Matching ____OF____

There are 21 10-letter words that match ____OF____. 7 are common words, such as HYDROFOILS and MICROFIBER. A rarer one is TOPLOFTILY. In this set, I is the most frequent open letter (18 words). 3 words contain a doubled letter.

Full list 21

hydrofoilsmicrofibermicrofichemicrofilmspianoforteretrofiredretrofiresbenzofuranmicrofaradphotoflashphotofloodenfeoffinginfeoffingintrofyingmicrofaunamicrofloramicroformsmicrofunginitrofurantoploftiertoploftily

About this list

Words
21 (7 common words)
Common example
hydrofoils
Rare example
toploftily
Doubled letters
3
Ending in S
4
Most frequent letter
I (18)

Questions

How many 10-letter words matching ____of____ are there?

21. 7 of them are common words.

What is a common example?

HYDROFOILS is among the common words in this set.