Literal translation
he is as green as an onion tail
Meaning
he's in fine fettle, full of energy
Explanation
This expression describes someone in great shape, full of energy, through the image of an onion tail's vivid green. Verd (green) qualifies es (is), and coua de sèbo (onion tail, the leafy green part rising above the bulb) supplies the comparison : this stalk, when fresh, shows a bright colour that signals the plant's vigour. Coume (like) introduces the classic Provençal comparison, which always favours a familiar object from the garden or kitchen over an abstraction. Green, associated here with health and youth, implicitly contrasts with the wilting and dull colour of something starting to fade : a person who is verd coume uno coua de sèbo is therefore someone who, whatever their age, keeps all their liveliness. The register is familiar and affectionate, readily used to compliment an older person on their energy or to describe someone clearly in good health and good spirits.