10-Letter Words Matching _Y__N_____

There are 20 10-letter words that match _Y__N_____. 5 are common words, such as SYNONYMIES and SYNONYMOUS. A rarer one is TYRANNISES. In this set, I is the most frequent open letter (16 words). 8 words contain a doubled letter.

Full list 20

synonymiessynonymoustyrannicaltyrannizedtyrannizescylindroiddysentericgynandroushypanthiumsynonymitysynonymizetyrannizercylinderedeyednessesgynandrieshymeneallypyranosidesynonymisttyrannisedtyrannises

About this list

Words
20 (5 common words)
Common example
synonymies
Rare example
tyrannises
Doubled letters
8
Ending in S
7
Most frequent letter
I (16)

Questions

How many 10-letter words matching _y__n_____ are there?

20. 5 of them are common words.

What is a common example?

SYNONYMIES is among the common words in this set.