Gradient and Stingray

Gradient noun - The degree to which something rises up from a position level with the horizon.

Stingray and gradient are semantically related. In some cases you can use "Stingray" instead a noun "Gradient".

Stingray noun - Large venomous ray with large barbed spines near the base of a thin whiplike tail capable of inflicting severe wounds.

Gradient and stingray are semantically related. Sometimes you can replace term "Gradient" with "Stingray", this nouns are similar.