Arthropod and Arachnid

Arthropod noun - Invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin.

Arachnid and arthropod are semantically related. in bug topic. In some cases you can use "Arachnid" instead a noun "Arthropod".

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

Arthropod and arachnid are semantically related. You can use "Arthropod" instead a noun "Arachnid".