fastigium

[Latin fastīgium, apex, height.]

noun

The highest point or state: acme, apex, apogee, climax, crest, crown, culmination, height, meridian, peak, pinnacle, summit, top, zenith. Informal payoff. See high/low.

1. The pediment of a portico, so-called in ancient architecture because it followed the form of the roof.
2. The crest or ridge of a roof.

1. The summit of the roof of the fourth ventricle of the brain.
2. The acme or period of full development of a disease.

[L.]
1. the highest point in the roof of the fourth ventricle of the brain.
2. the acme, or highest point. For example in fever: the high point of constant temperature between the increment and the decrement.