Arachnid and Butterfly

Arachnid noun - Air-breathing arthropods characterized by simple eyes and four pairs of legs.

Butterfly and arachnid are semantically related In some cases you can use "Butterfly" instead a noun "Arachnid".

Butterfly noun - Diurnal insect typically having a slender body with knobbed antennae and broad colorful wings.

Arachnid and butterfly are semantically related in bug topic. Sometimes you can use "Arachnid" instead a noun "Butterfly".