←
Proto-Germanic *būlǭ (inherited)
←
Middle High German biule (inherited)
←
Old High German būlla (inherited)
←
Old High German bulla (mention)
←
Old High German būilla (mention)
←
Old High German būla (mention)
→
Middle Norwegian boldi (cognate)
→
Saterland Frisian Buule (cognate)
→
Silesian ojla (borrowed)