Definition of pissabed in English:

Late 16th century: from the verb piss (because of its diuretic properties) + abed, suggested by the French name for the dandelion, pissenlit.

• dandelion from Late Middle English:

  The toothed leaves of the dandelion explain the origin of its name. French dent-de-lion means ‘lion's tooth’. The name came into English in the late Middle Ages. The usual term for the flower in French is now pissenlit, which has a parallel in English pissabed (mid 16th century), another name for the dandelion. The plant was formerly well known for its diuretic properties.