The suffix -ose (/oʊz, oʊs/) is used in organic chemistry to form the names of sugars. This Latin suffix means "full of", "abounding in", "given to", or "like".^[1] Numerous systems exist to name specific sugars more descriptively. The suffix is also used more generally in English to form adjectives from nouns, with the sense "full of",^[2] as in "verbose": wordy, full of words.

Monosaccharides, the simplest sugars, may be named according to the number of carbon atoms in each molecule of the sugar: pentose is a five-carbon monosaccharide, and hexose is a six-carbon monosaccharide. Aldehyde monosaccharides may be called aldoses; ketone monosaccharides may be called ketoses.

Larger sugars such as disaccharides and polysaccharides can be named to reflect their qualities. Lactose, a disaccharide found in milk, gets its name from the Latin word for milk combined with the sugar suffix; its name means "milk sugar". The polysaccharide that makes up plant starch is named amylose, or "starch sugar"; see amyl.

There are these theories about the origin of the -ose suffix in chemistry:-

1. Derived from glucose, an important hexose whose name came from Greek γλυκύς = "sweet".
2. Derived from sucrose, whose name came from Latin sucrum = "sugar" plus the common Latin adjective-forming suffix -ōsus; Latin sucrosus would mean "sugary".