decem-, decim-, deci-, dec-

(Latin: ten; also, a decimal prefix used in the international metric system for measurements)

In the metric [decimal] system, deci- [DE si] is used to show 1/10 of a unit, as 10-1 [0.1]; tenth [U.S.] and tenth part [U.K.]. The metric symbol is d.

dime
duodecennial
duodecimal
duodecimally
duodecimo
novemdecillion
A cardinal number (1060) represented in the U.S. by the number "1" followed by 60 zeros, and in Great Britain a number (10114) by "1" followed by 114 zeros.
quindecennial
1. Happening once every fifteen years or a fifteenth anniversary.
2. Lasting for fifteen years.
3. A fifteenth year of existence or duration; fifteenth anniversary.

From Latin quindecim, "fifteen" [quinque, "five" plus decem, "ten" plus -ennial, "year"].

undecennary
undecennial

Related "metric" families: yotta; zetta; exa; peta; tera; giga; mega; kilo; hecto; deka; centi; milli; micro; nano; pico; femto; atto; zepto; yocto.