Without expense or cost; free from financial burden.
From 'expense' plus the suffix '-less' (Old English '-læs' meaning without or lacking). The '-less' suffix has been used to create opposites in English since before the Norman Conquest in 1066.
The suffix '-less' is one of English's most generous tools—it lets you attach it to almost any noun to say 'without that thing.' 'Expenseless' is theoretically perfect English, but we typically just say 'free' or 'costless' instead.
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