WordNet sense 1 (a slender or elongated structure that supports a plant or fungus or a plant part or plant organ):

stalk

WordNet sense 2 ((linguistics) the form of a word after all affixes are removed):

base, radical, root, theme, root word

WordNet sense 3 (cylinder forming a long narrow part of something):

shank

WordNet sense 4 (front part of a vessel or aircraft):

bow, fore, prow, bow

WordNet sense 5 (a turn made in skiing; the back of one ski is forced outward and the other ski is brought parallel to it):

stem turn

WordNet sense 6 (stop the flow of a liquid):

halt, stanch, staunch