The floor of a non-negative number a: the greatest integer that is smaller than or equal to a. For example,⎣5⎦ = 5, and⎣5.9⎦ = 5.
NIST SP 800-106
The floor of x; the largest integer ≤ x. For example,⎿5⏌ = 5 and⎿6.9⏌ = 6.
NIST SP 800-135 Rev. 1