(idiomatic) Often in the phrase on cloud nine: a state of bliss, elation or happiness. / (idiomatic, possibly nonstandard) A state of fantastic or impractical dreaming or thinking.

(baseball, slang, 1800s) The team.

(idiomatic) Very fancily or formally dressed; wearing very showy or splendid clothing.

(idiomatic) In a state of elation; very happy; blissful.

The cardinal number occurring after eight hundred ninety-nine and before nine hundred one, represented in Arabic numerals as 900. Ordinal: nine-hundredth.

(especially of a cat) Durability; near immunity to damage; remarkable ability to survive.

(historical) A 5.9-inch artillery shell of the kind used by Germany in World War I.

From 9 a.m. to 5 p.m.

A typical working day.

Alternative spelling of nine-ball