Early 17th century. From post-classical Latin quadragena period of forty days, forty-day fast, Lent, use as noun of neuter of classical Latin quadrāgēnī forty each, forty from quadrāgintā forty + -ēnī, suffix forming distributive adjectives.
Definition of quadragene in US English:
quadragene
nounˈkwɒdrədʒiːn
rare, historical
A forty-day indulgence.
Origin
Early 17th century. From post-classical Latin quadragena period of forty days, forty-day fast, Lent, use as noun of neuter of classical Latin quadrāgēnī forty each, forty from quadrāgintā forty + -ēnī, suffix forming distributive adjectives.