Hi MrP,
There's one restriction: X can't be found in an ordinary English dictionary and X doesn't seem to have meaning(s).
'Fisherman' can be found in an ordinary English dictionary, but 'Lindeman', 'Kohl', 'Gilbey','Lawry'...etc. can't.
'Lay' is a word and has meanings and most non-native speakers wouldn't recognize it's a surname. Whether it has a special meaning or i