Gray whale and Whalebone whale

Gray whale noun - Medium-sized greyish-black whale of the northern Pacific.

Whalebone whale and gray whale are semantically related. In some cases you can use "Whalebone whale" instead a noun phrase "Gray whale".

Whalebone whale noun - Whale with plates of whalebone along the upper jaw for filtering plankton from the water.

Gray whale and whalebone whale are semantically related. Sometimes you can replace phrase "Gray whale" with "Whalebone whale", this phrases are similar.