deci-

1.
a combining form meaning “tenth,” used in words denoting units of the metric system (deciliter); on this model, extended to other systems (decibel).
Compare deca-.
Origin
< French déci- < Latin decimus tenth
British Dictionary definitions for deci-

deci-

prefix
1.
denoting one tenth; 10–1: decimetre, d
Word Origin
from French déci-, from Latin decimus tenth
Word Origin and History for deci-

in the metric system, word-forming element denoting weights of one-tenth of the standard unit of measure, 1801, from French deci-, taken arbitrarily from Latin decimus "tenth," from decem "ten" (see ten).

deci- in Medicine

deci- pref.
One tenth (10-1): decibel.

deci- in Science
deci-  
A prefix that means "one tenth," as in deciliter, one tenth of a liter.