noun

• (obsolete) A shallow bowl used for a single serving of a drink or liquidy food.
  "[…] Mr. John Knightley, ashamed of his ill-humour, was now all kindness and attention; and so particularly solicitous for the comfort of her father, as to seem—if not quite ready to join him in a basin of gruel—perfectly sensible of its being exceedingly wholesome […]"
• (geography) An area of land from which water drains into a common outlet; drainage basin.
  "Devils Lake is where I began my career as a limnologist in 1964, studying the lake’s neotenic salamanders and chironomids, or midge flies. […] The Devils Lake Basin is an endorheic, or closed, basin covering about 9,800 square kilometers in northeastern North Dakota."
• (geography) A shallow depression in a rock formation, such as an area of down-folded rock that has accumulated a thick layer of sediments, or an area scooped out by water erosion.