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.
A number that can be made by dividing two integers. (Note: integers have no fractions.) The word comes from ratio. Examples: â¢ 1/2 is a rational number (1 divided by 2, or the ratio of 1 to 2) â¢ 0.75 is a rational number (3/4) â¢ 1 is a rational number (1/1) â¢ 2 is a rational number (2/1) â¢ 2.12 is a rational number (212/100) â¢ â6.6 is a rational number (â66/10) But Pi is not a rational number, it is an Irrational Number.