Definitions

1. verb

to make or become soft or weak, especially through overuse or excessive heat

“The sun beat down on the fabric, causing it to mullen and lose its shape.”

2. noun

a soft, weak, or half-rotten part of something

“The mullen in the old rope caused it to break unexpectedly.”

3. noun

a type of grass, especially in the genus Elymus

“The mullen in the field was a common sight during the summer months.”