Tyrannosaur and Theropod dinosaur

Tyrannosaur noun - Large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America.

Theropod dinosaur and tyrannosaur are semantically related. In some cases you can use "Theropod dinosaur" instead a noun "Tyrannosaur".

Theropod dinosaur noun - Any of numerous carnivorous dinosaurs of the Triassic to Cretaceous with short forelimbs that walked or ran on strong hind legs.

Tyrannosaur and theropod dinosaur are semantically related. Sometimes you can replace term "Tyrannosaur" with "Theropod dinosaur", this terms are similar.