What's the difference between "lean" and "thin", if any?
Are they interchangeable in such sentence: she is a lean woman?
Does "lean" has a more negative tone?
Can you give some more examples? Thanks in advance!

Question

Answer

It's the other way round - 'lean' has a more positive tone than 'thin'. 'Thin' suggests that the person may be underfed and bony, whereas 'lean' suggests that they are fit and have no excess fat.