The quality of being exceptionally effulgent (giving off light). / The quality of having extraordinary mental capacity. / (chiefly Britain) Magnificence; resplendence.

plural of brilliance

A shining quality; brilliance. / An act of being brilliant. / (chess) A spectacular and beautiful game of chess, generally featuring sacrificial attacks and unexpected moves.

plural of brilliancy

When you don't have all the facts or have a brilliant explanation, you can often convince people or win an argument by using bullshit.