Definition of lumbar puncture. : puncture of the subarachnoid space in the lumbar region of the spinal cord to withdraw cerebrospinal fluid or inject anesthetic drugs.
Rational Numbers A rational number is a number that can be written as a ratio. That means it can be written as a fraction, in which both the numerator (the number on top) and the denominator (the number on the bottom) are whole numbers. The number 8 is a rational number because it can be written as the fraction 8/1.
Rational Function. A function that is the ratio of two polynomials. It is Rational because one is divided by the other, like a ratio. Note: the polynomial you are dividing by cannot be zero. function that is the ratio of two polynomials. It is Rational because one is divided by the other, like a ratio. Note: the polynomial you are dividing by cannot be zero.