oil spot

plural oil spots · alternative oilspot

1. A spot consisting of oil.
   1. A soiled spot on clothing, a tablecloth, etc., where some oil was absorbed; a similar spot on a driveway, puddle, etc., where some oil is lying.
   2. An oil film over an area of the ocean after an oil spill.

      Synonyms: oil slick, oilpatch

2. biologyOne of the yellow spots, often circular in shape, on the upper leaf surface of grapevines in the early stages of downy mildew (caused by Plasmopara viticola infection).