1. Huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic
   - apatosaur, apatosaurus, brontosaur, brontosaurus, thunder lizard

Type of: sauropod, sauropod dinosaur

Part of: genus Apatosaurus, genus Brontosaurus

Encyclopedia: Apatosaurus excelsus

• on the line
• on the loose
• on the mend
• on the nail
• on the nose
• on the off chance
• on the offensive
• on the one hand
• on the other hand
• on the QT
• on the qui vive
• on the road
• on the rocks
• on the ropes
• on the run
• on the side
• on the sly
• on the spot
• on the spur of the moment
• on the table
• on the trot
• on the up-and-up
• on the way
• on the whole
• on the wing