-cule1

1.
variant of -cle1 :
animalcule; molecule; reticule.
Origin
(< F) < Latin -culus, -cula, -culum; see -cle1

-cule2

1.
variant of -cle2 :
ridicule.
Origin
(< F) < Latin -culum, -cula; see -cle2
British Dictionary definitions for -cule

-cule

suffix
1.
indicating smallness: animalcule
Word Origin
from Latin -culus, diminutive suffix; compare -cle
Word Origin and History for -cule

word-forming element used to make diminutives, from French -cule or directly from Latin -culus (masc.), -cula (fem.), -culum (neuter).