Initialism of highly-enriched uranium.

(of an approach to problem solving, learning, or discovery) That employs a practical method not guaranteed to be optimal or perfect; not following or derived from any theory.

A heuristic method. / The art of applying heuristic methods. / (computing) A technique designed for solving a problem when classic methods are too slow or fail to find any exact solution.

in a heuristic manner

plural of heuristic

The study of heuristic methods and principles. / Heuristic methods and approaches considered collectively.

Knowledge derived from empirical study and practical adoption of experience.

Of or relating to discovery or invention / (logic) The branch of logic concerned with discovery or invention

plural of heuretic

(Scotland, Northumbria) A steep crag or cliff, especially one with overhanging sides / (Scotland, Northumbria) A glen with steep, overhanging sides