Nebulous (adjective) غیر واضح، دھندلا

in the form of a cloud or haze; hazy.
Example: “a giant nebulous glow”
Insidious (adjective) پرفریب، ناپاک شیطانیت والا

proceeding in a gradual, subtle way, but with very harmful effects.
Example: “sexual harassment is a serious and insidious problem”