The term 'just fine' can be expressed in a variety of ways. The nine-letter word 'COPACETIC' is an informal term used to describe something that is satisfactory or acceptable. The four-letter word 'FAIR' is often used to describe something that is satisfactory, but not necessarily excellent. The three-letter word 'COP' is a slang term for 'OKAY' or 'all right'. The three-letter word 'aok' is another slang term for 'OKAY' or 'all right'. Finally, the four-letter word 'OKAY' is a commonly used term to express that something is satisfactory. All of these words can be used to express the sentiment of 'just fine'.