Difference between Octonary and Eight

Octonary

Part of speech: noun

Definition: A group of eight things

Part of speech: adjective

Definition: Of eighth rank or order. Consisting of eight things

Eight

Part of speech: numeral

Definition: The cardinal number occurring after seven and before nine. Ordinal: eighth.Describing a set or group with eight components.

Part of speech: noun

Definition: Any of the four cards in a normal deck with the value eight.The digit/figure 8.A light, narrow rowing boat, especially one used in competitive rowing, steered by a cox, in which a eight rowers each have two oarsA race in which such craft participate

Example sentence: Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins.