Without belief in God, or showing a lack of respect for religion and moral values.
From Old English 'god' plus the suffix '-less' (without). The '-less' suffix is one of the most productive word-builders in English, able to attach to almost any noun.
In medieval times, calling someone 'godless' was the worst possible insult, but in the Enlightenment and modern era, some people began reclaiming it proudly as part of the atheism movement!
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