From the Latin [vena], meaning "vein". Some early authors postulated that the term derivates from the Latin word [venio] meaning "to come", because the blood in the veins "comes in" to the heart. There are two root terms meaning "vein", the first is the Latin derivated [-ven-], as in the terms venous and intravenous. The second root term is Greek [-phleb-], as in the terms phlebectomy, phlebotomy, and phlebotomist. Peripheral veins have internal one-way valves, while most of the central veins (in the trunk) do not present with valves. Failure of a peripheral venous valve can lead to dilation of the vein, condition called a varix.

Venous: pertaining to a vein
Intravenous: inside or within a vein
Phlebectomy: removal of a vein
Phlebotomy: to open a vein