Bulgarisation means making something look, sound or feel more Bulgarian. Just like how when you decorate your room with your favorite colors and toys/items, you are making it look and feel more like it belongs to you.
Similarly, when people migrate and live in a new country, they tend to adopt some aspects of that country's culture, language, and way of life to fit in and feel like they belong. This process of adopting or incorporating new culture and traditions is called integration.
Similarly, when people try to make something more Bulgarian, it means they are trying to include more things that are specific to Bulgaria, like the language, food, music, and customs, into their lives or whatever they are creating.
For instance, if someone is cooking a Bulgarian dish and adds some spices or ingredients that are not typically used in Bulgarian cuisine, they may be criticized for not being authentic or not following the traditional recipe. In this example, the person is trying to bulgarise the dish by making it more Bulgarian.
Overall, bulgarisation is a term used to describe the process of incorporating Bulgarian elements or culture into something to make it more Bulgarian.