英[ˈhæbɪtˌfɔ:mɪŋ]
美[ˈhæbɪtˌfɔrmɪŋ]
These products aren't habit-forming by chance; it's by design.
2017年12月六级真题（第一套）阅读 Section BYet to many, email is the most habit-forming medium of all.
2017年12月六级真题（第一套）阅读 Section B"addictive drugs"
"addictive behavior"