Dander and Ragweed

Dander noun - Small scales from animal skins or hair or bird feathers that can cause allergic reactions in some people.

Ragweed and dander are semantically related In some cases you can use "Ragweed" instead a noun "Dander".

Ragweed noun - Any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma.

Dander and ragweed are semantically related in irritant topic. You can use "Dander" instead a noun "Ragweed".