'wiglet' is formed in English from 'wig' + the diminutive suffix '-let'. 'Wig' is a shortened form of 'periwig' (from French 'perruque' / Italian 'parrucca'), and '-let' comes from Old French '-let' (ultimately from Latin diminutive suffixes such as '-ellus').

'periwig' (from French 'perruque' / Italian 'parrucca') shortened in English to 'wig' in the 17th century; the modern coinage 'wiglet' was formed later by adding the diminutive '-let' to mean a small wig.

Originally related to 'periwig' meaning a full wig; over time 'wig' came to mean any wig and 'wiglet' developed to denote a smaller, partial wig or hairpiece.