Threshold

A threshold is what you step across when you enter a room. A threshold takes you from one place into another, and when you're about to start something new, you're also on a threshold.

• Pronunciation: /ˈθreʃhəuld/
  
• English Description: the entrance to a room or building, or the area of floor or ground at the entrance
  
• Chinese Translation: 开端(Kai1 Duan1)
  
• Spanish Translation: umbral
  
• STORY: A threshold is a point of departure or transition. Graduation can mark a threshold — when you graduate from circus school, you're standing at the threshold of your new career as a trapeze artist. Another kind of threshold is a limit or boundary. If you have a high threshold for pain, you can tolerate a lot of it, and your dentist can drill away without worrying about your squirming and howling.
  

EXAMPLE SENTENCE:

• The temperature mark is the warming threshold at which governments say climate change could become catastrophic and irreversible.Reuters May 19, 2015
  

• Of the seven products that did not carry gluten-free labels, four tested positive for gluten, including two that exceeded the F.D.A. threshold.
  

P.S: New word description, story and part of "EXAMPLE SENTENCE" are cited in Vocabulary.com