penumbra /pe-numˈbrə/

1. A partial or lighter shadow round the perfect or darker shadow produced by an eclipse or by a large unfocused light source shining on an opaque object
2. The less dark border of a sunspot or any similar spot
3. The part of a picture where the light and shade blend into each other

• thighs
• thigmotactic
• thigmotactically
• thigmotaxis
• thigmotropic
• thigmotropism
• thigmotropisms
• thigs
• thilk
• thill
• thiller
• thillers
• thill-horse
• thills
• thimble
• thimble case
• thimble cases
• thimbled
• thimbleful
• thimblefuls
• thimblerig
• thimblerigged
• thimblerigger
• thimbleriggers
• thimblerigging