šāmīr שָׁמִיר ‘thorn’ (Hebrew)

Etymology^?: from šāmar שָׁמַר ‘to keep’ in the original sense of pricking
Roots: שׁמר

šāmīr n, m
1) thorn(s), adamant, flint
 1a) thorns, thorn-bushes
 1b) adamant (as sharp)
 1c) a sharp stone, flint
  1c1) perhaps a diamond