Synonyms for Knob (same or very similar meaning)
WordNet sense 1 (any thickened enlargement):
node, thickening
WordNet sense 2 (an ornament in the shape of a ball on the hilt of a sword or dagger):
pommel
WordNet sense 3 (a circular rounded projection or protuberance):
boss
From the ODE community, based on WordNet
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