More on Threshold from Infoplease:

• Weighted Average Poverty Thresholds for Families, 1960–2010 - The following table lists the income thresholds for individuals and families that determine who is living in poverty. Thresholds vary by size of family. Region of the United States is not considered; the thresholds each cover the entire U.S.
• photoelectric threshold: meaning and definitions - photoelectric threshold: Definition and Pronunciation
• threshold: meaning and definitions - threshold: Definition and Pronunciation
• Geiger-Müller threshold: meaning and definitions - Geiger-Müller threshold: Definition and Pronunciation
• Threshold - Threshold Properly the door-sill, but figuratively applied to the beginning of anything; as, the ...