Numeral or
number prefixes are
prefixes derived from
numerals or occasionally other
numbers. In English and other European languages, they are used to coin numerous series of words, such as
unicycle – bicycle – tricycle,
dyad – triad – decade, biped – quadruped, September – October – November – December, decimal – hexadecimal, sexagenarian – octogenarian, centipede – millipede, etc. There are two principal systems, taken from
Latin and
Greek, each with several subsystems; in addition,
Sanskrit occupies a marginal position. There is also an international set of
metric prefixes, which are used in the
metric system, and which for the most part are either distorted from the forms below or not based on actual number words.
