Stem - as usual this can be a noun (a stem, the stem) or a verb (to stem, to stem from), and although it all looks like the same word, it has different meanings which come from different origins. One meaning is like "kmeň" or "stonka", the long, straight, slim but strong part of a plant or tree holding up the flower or the crown. It's also the thin "leg" of a wine-glass.

The brain stem grows upwards out of the spinal cord into the lower brain, and provides stem cells. The stem of a boat or ship is the strong, upright, central piece of wood or steel curving up to the prow, which the sides of the vessel are attached to at the front. All these include the notion of growing up or out of some origin, so there's the idea of "vzniknúť", typically for abstract things like ideas, situations or problems.

The other meaning appears in expressions like "to stem the flow", meaning physically to limit or stop the movement of liquid, like blood from a wound, or metaphorically, like measures (opatrenia) to stem the spreading effects of the financial crisis.