YIELD CURVE SLOPE
Yield curves also describe the amount of difference between short-term and long-term rates. A yield curve that depicts the customary situation of long-term rates higher than short-term rates is called an upward sloping or positively sloped yield curve. A yield curve depicting the less common occurrence of short-term rates higher than long-term rates is called a downward sloping, negatively sloped, or inverted yield curve. When long-term rates are much higher than short-term rates, the yield curve is steep. When long-term rates are virtually the same as short-term rates, the yield curve is flat.American Banker Glossary