noun
A specialized knife or chisel for carving wood, linoleum, or other materials, especially in printmaking and sculpture.
版画を彫るために、新しい彫刻刀を買った。
I bought a new carving knife to make woodblock prints.
Sharpening the blade of a carving chisel is difficult.
小刀 is a small knife or utility knife, not necessarily specialized for carving like 彫刻刀.
Compound of 彫刻 (carving, sculpture) and 刀 (sword, blade). The exact historical derivation is uncertain, but the word transparently means 'carving blade'.