Germ
late Middle English (in germ (sense 2)): via Old French from Latin germen ‘seed, sprout’. germ (sense 1) dates from the late 19th century.
wiktionary
From Middle French germe, from Latin germen(“bud, seed, embryo”). Doublet of germen.
etymonline
germ (n.)
mid-15c., "bud, sprout;" 1640s, "rudiment of a new organism in an existing one," from French germe "germ (of egg); bud, seed, fruit; offering," from Latin germen (genitive germinis) "spring, offshoot; sprout, bud," which is of uncertain origin, perhaps from PIE root *gene- "give birth, beget," with derivatives referring to procreation and familial and tribal groups.
The older sense is preserved in wheat germ and germ of an idea; sense of "seed of a disease" first recorded 1796 in English; that of "harmful micro-organism" dates from 1871. Germ warfare is recorded from 1919.