What is de groote?

Some articles on de groote:

My Bonny Light Horseman - Plot Introduction
... After plying de Groote with Cognac laced with Paregoric and prying Napoleon's troop movements out of him, his wife arrives brandishing pistols ... The ensuing altercation injures de Groote, disabling him and attracting the attention of the police ...
Thierry De Groote
... Thierry De Groote (born on 9 May 1975 in Deinze, Belgium) is a professional road bicycle racer ... De Groote lives in Nazareth, Belgium ...