easygoing
Word family
Synonym discussion
Sense: adjective/1
All four words describe a calm, untroubled temperament, but they differ in register and scope. 'Easygoing' is the most neutral and widely understood term; it implies someone who does not get upset easily and adapts well to others. 'Laid-back' is more informal and common in American English, often suggesting a deliberate rejection of stress or urgency — a laid-back person might arrive late and not worry about it. 'Relaxed' has a broader application: a person, atmosphere, or schedule can be relaxed, but it does not specifically carry the social-flexibility meaning of 'easygoing.' 'Mellow' is informal and focuses on a gentle, good-natured calm, often with the nuance that someone has become calmer with age or experience — you would say 'he has mellowed over the years' but not 'he has easygoinged.' For a learner at B1 level, 'easygoing' and 'relaxed' are the safest choices; 'laid-back' is fine in casual conversation.
Common collocations
Etymology
'Easygoing' is a compound of the adjective 'easy' (from Old French 'aisie', meaning 'comfortable, at ease') and the present participle 'going' (from Old English 'gān', meaning 'to move, proceed'). It was first used in the 17th century to describe a horse that moved smoothly and without effort. By the 19th century, the meaning had shifted from physical ease of movement to a person's relaxed, flexible temperament — the sense that is most common today.