lumbar puncture
noun /ˈlʌmbə pʌŋktʃə(r)/
/ˈlʌmbər pʌŋktʃər/
[countable, uncountable] (North American English also spinal tap [countable])
(medical)- a medical procedure in which liquid is removed from the lower part of the spine with a hollow needle, usually in order to diagnose a medical problem (= identify what it is)