The changes are insidious, and will not produce a noticeable effect for 15 to 20 years.
⇑ Translate the sentence above by Google ⇑
Related: noticeable
Prev: The result of this experiment was not noticeable for a long period.
Next: Usually not meant to be noticeable, it often provides a tone or an emotional attitude toward the story and/or the characters depicted.
