woolly

Impulse by Dr David Lewisを読んでいます。
In some branches of science 'impulse' has an unambiguous meaning.
...
'Impulses,' he wrote, '[are] ephemeral thoughts usually tied to forceful urges.' Many of the definitions offered by later psychologists were equally woolly and, on occasions, mutually contradictory.
上の引用文に出てきた "woolly" は語感からしてフワフワしてしっかりとしていない意味の様ですが、辞書で確認します。
・Oxford English Dictionary: Vague or confused in expression or character.: woolly thinking
・Collins Dictionary: If you describe a person or their ideas as woolly, you are criticizing them for being confused or vague.: ...a weak and woolly Government
・Cambridge English Dictionary: Woolly ideas and thinking are confused and not clear, and have not been considered carefully enough: It's the woolly thinking behind the book that I find so infuriating.