premoult
/ˌpriːˈməʊlt/(also premolt) Zoology
adjective
Existing or occurring just before a change of plumage in birds, the shedding and replacement of the integument of arthropods, etc.
noun
A premoult stage or period.
Origin
1930s; earliest use found in Proceedings of the Royal Society of London. From pre- + moult.