Synonyms for High-level (same or very similar meaning)
WordNet sense 1 (at an elevated level in rank or importance):
upper-levelWordNet sense 2 (of or characteristic of high rank or importance):
superiorWordNet sense 3 ((literal meaning) being at or having a relatively great or specific elevation or upward extension (sometimes used in combinations like `knee-high')):
highFrom the ODE community, based on WordNetadd/edit