Countable Nouns That Start with OS and End with IUM

Explore 5 verified English countable nouns starting with OS and ending with IUM, including Ostium, Osmiridium, Ostensorium, Ossarium and Osmeterium. Sort these count nouns with singular and plural forms by word length for ESL grammar practice, determiner usage, and plural spelling below, or review singular and plural count rules in our noun grammar guide.

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Starts with OSM
2 words
osmiridium
osmeterium
Starts with OSS
1 words
ossarium
Starts with OST
2 words
ostium
ostensorium

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