What is the meaning of the surname ‘Willemyns’ or ‘Willemijns’?

Answer

~~There is a very good reference work, which can be found in almost every public library, the Dictionary of Family Names in Belgium and Northern France (by Dr. Frans Debrabandere, published in a revised version by LJ Veen / Het Taalfonds in 2003) . It contains, among other things, all variants and the first sources of each surname.

Willemijns/Willemyns is clearly a patronymic, which refers to a father or ancestor called Willem.