brilliant
Outstanding, excellent, or clever; of exceptionally high quality or intelligence.
Das war eine brillante Analyse der aktuellen politischen Lage.
That was a brilliant analysis of the current political situation.

Loading your saved state.
Outstanding, excellent, or clever; of exceptionally high quality or intelligence.
Das war eine brillante Analyse der aktuellen politischen Lage.
That was a brilliant analysis of the current political situation.

You can recognize the meaning from the noun that 'brilliant' describes. If it refers to abstract things like an idea or performance, it means 'hervorragend' (outstanding). If it refers to concrete objects like jewelry or eyes, it means 'glänzend' (shiny/brilliant).
Er hatte eine brillante Idee, um das Problem zu lösen.
He had a brilliant idea for solving the problem.
In the meaning 'hervorragend' (outstanding), 'brilliant' is often combined with intellectual or creative achievements. Typical examples are: 'eine brillante Idee' (a brilliant idea), 'eine brillante Analyse' (a brilliant analysis), 'ein brillanter Redner' (a brilliant speaker), or 'eine brillante Vorstellung' (a brilliant performance).
Die Pianistin gab ein brillantes Konzert.
The pianist gave a brilliant concert.
The word 'brilliant' in the sense of 'ausgezeichnet' (excellent) belongs to an elevated style. It expresses very high praise and is stronger than 'sehr gut' (very good).
Ihre Argumentation in der Debatte war einfach brilliant.
Her argumentation in the debate was simply brilliant.
bad
'schlecht' and 'brilliant' can both evaluate a performance, idea, or quality, but they mean almost the opposite. 'schlecht' says that something is not good or has many mistakes. 'brilliant' is much stronger than just 'good' and means exceptionally good, clever, or impressive. For ordinary good things, 'brilliant' is often too strong. It fits especially when a solution, a presentation, or an idea really stands out.

Annas Vorschlag war brilliant, weil er das Problem sofort gelöst hat.
Anna's suggestion was brilliant because it solved the problem immediately.
Der Bericht war schlecht geschrieben und enthielt viele Fehler.
The report was badly written and contained many mistakes.