13-Letter Words Matching ___I_____O___

There are 24 13-letter words that match ___I_____O___. 10 are common words, such as ANTISPASMODIC and BIDIRECTIONAL. A rarer one is RADIOISOTOPIC. In this set, I is the most frequent open letter (20 words). 9 words contain a doubled letter.

Full list 24

antispasmodicbidirectionalbusinesswomanbusinesswomendisillusionedoscilloscopesradioisotopessocioeconomicunlikelihoodsvivisectionalactinomycosesactinomycosisantipsychoticbasidiosporesconidiophoresoscilloscopicactinomycoticantibillboardantimetabolicarbitrationalimmigrationaloscillationalradiobiologicradioisotopic

About this list

Words
24 (10 common words)
Common example
antispasmodic
Rare example
radioisotopic
Doubled letters
9
Ending in S
7
Most frequent letter
I (20)

Questions

How many 13-letter words matching ___i_____o___ are there?

24. 10 of them are common words.

What is a common example?

ANTISPASMODIC is among the common words in this set.