witches' knickers

Noun

Britain plural plural-only slang

(slang, Britain) plastic bags snagged in trees and bushes.

Japanese Meaning

（スラング、英国）木や低木に引っかかったプラスチック製の袋

After last night's storm, the hedgerows looked terrible, filled with witches' knickers that fluttered like flags.

昨夜の嵐の後、生け垣はひどい有様で、木や藪に引っかかったビニール袋が旗のようにはためいていた。

Sense（1）

(slang, Britain) plastic bags snagged in trees and bushes.