What does "sandbur" mean?

Any of several grasses, of the genus Cenchrus, found in the south-eastern United States, that has a spiny burr

Sandbur

Common synonyms include: burr grass, cenchrus tribuloides, field sandbur, sandspur, sandspur grass, spiny burr.

/ˈseənd.bəɹ/ noun

noun ·Rare ·Advanced level

Noun

1
Any of several grasses, of the genus Cenchrus, found in the south-eastern United States, that has a spiny burr
2
grass of the eastern United States and tropical America having spikelets enclosed in prickly burs wordnet

From sand + bur.