Mad apple and Solanaceous vegetable

Mad apple noun - Egg-shaped vegetable having a shiny skin typically dark purple but occasionally white or yellow.

Solanaceous vegetable and mad apple are semantically related. In some cases you can use "Solanaceous vegetable" instead a noun phrase "Mad apple".

Solanaceous vegetable noun - Any of several fruits of plants of the family Solanaceae; especially of the genera Solanum, Capsicum, and Lycopersicon.

Mad apple and solanaceous vegetable are semantically related. Sometimes you can replace phrase "Mad apple" with "Solanaceous vegetable", this phrases are similar.