6-letter words with I as the 4th letter and O as the 5th letter

The pattern is ___IO_: three letters come before I, and one follows O. Action, nation, and option show how often this fixed middle appears in everyday words. The list also includes specialist entries such as cation and pinion, so familiar vocabulary is only part of the picture.

The pattern at a glance

• There are 63 tournament-dictionary matches for the fixed I-O middle.
• Eighteen matches fall among the top 25,000 English words by frequency.
• Thirty-eight words end in N, making N the dominant final letter.
• Junior leads the Scrabble scores at 13 points.

How many 6-letter words have I as the 4th and O as the 5th?

There are 63 matches. Their endings are unusually concentrated: 38 finish with N, including action, region, nation, and option.

Another 13 end in S, as in ratios, radios, and audios. Only five end in R, with senior and junior among the examples.

The starting letters spread out more evenly. P leads with six words, while A, L, and R each start five. That gives you different routes through the pattern: try familiar starts such as A or R first, then test P if those letters do not fit.

Which matches score well, and where are they accepted?

Junior scores 13 Scrabble points, the highest score in this group; havior follows at 12, and pavior at 11. Period and vision each score 9. The contrast matters: a familiar word can fit the pattern, but a less familiar one can earn more points.

Dictionary coverage is not identical across games: Collins includes 62 matches, NWL2023 includes 57, and ENABLE includes 53. The full count combines words found in at least one of those tournament dictionaries, so not every game accepts all 63; check your game's word list.

For a quick solve, use the ending before guessing the first letter. N covers 38 options, while S covers 13; that sharp split narrows the field faster than testing every possible opening.