In an easy-going, relaxed, or unconcerned manner; without haste or anxiety.
From 'easy-going' (easy + going, meaning proceeding in a relaxed way) + '-ly' (adverbial suffix). 'Easy-going' itself is a compound adjective that emerged in English around the 18th century.
The word 'easy-going' is relatively young in English—it doesn't appear in Shakespeare—and it perfectly captures how language evolves to describe modern attitudes toward life and stress. The '-ly' adverbial form lets us verb-ify a relaxed lifestyle.
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