moulting vs molting

moulting and molting both are nouns.

Word	Noun	Adjective	Verb	Adverb
moulting	Yes	No	No	No
molting	Yes	No	No	No

As nouns, moulting and molting are synonyms defined as:

moulting and molting: periodic shedding of the cuticle in arthropods or the outer skin in reptiles

Other synonyms of moulting include ecdysis, molt, moult.

moulting (noun)	molting (noun)
periodic shedding of the cuticle in arthropods or the outer skin in reptiles	periodic shedding of the cuticle in arthropods or the outer skin in reptiles