Any continuous cumulative frequency curve, such as the one illustrated above in the right figure.

Kenney, J. F. and Keeping, E. S. "Ogive Curves." §2.7 in Mathematics of Statistics, Pt. 1, 3rd ed. Princeton, NJ: Van Nostrand, pp. 29-31, 1962.

CITE THIS AS:

Weisstein, Eric W. "Ogive." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/Ogive.html