Albert Camus opens Le Mythe de Sisyphe (1942) by declaring there is but one truly serious philosophical problem, suicide, and defines the absurd as the confrontation between human nostalgia for clarity and the unreasonable silence of the world. His rule is that the absurd must be lived, not escaped: neither physical suicide nor what he calls philosophical suicide, leaping to faith or false hope, is permitted. The essay was published in occupied France, which is not incidental context.
Popular culture flattens the absurd into nihilism with better lighting: nothing matters, so do what you want. Camus explicitly rejected this: the absurd commands revolt, freedom, and passion, and forbids the shrug. The universe not keeping score is, for him, a call to presence, not permission to check out.
Camus's subtle move is relational: the absurd is neither in the human nor in the world but in their co-presence, a third thing. Kill the demand for meaning and you have peace, kill the world's silence and you have religion, keep both and you have the absurd, which he treated as the only honest address to live at.
If the absurd lives only in the confrontation, what dies first when you stop demanding an answer?