penumbra meaning - definition of penumbra by Mnemonic Dictionary

Mnemonics (Memory Aids) for penumbra

pen under an umbrella will be invisble unders umbrella's shadow

17 6

use pen on bra to take the partial shadow of breast

9 13

Nimbus clouds create shaddows.

1 2

when you use umbrella there is shadow ,not the direct rays.

1 0

penumbra