Bill found by queen for vessel (6)
I believe the answer is:
beaker
'for vessel' is the definition.
(beaker is a kind of vessel)
'bill found by queen' is the wordplay.
'bill' becomes 'beak' (synonyms).
'found' means one lot of letters go next to another.
'by queen' becomes 'er' (abbreviation for Elizabeth Regina. I am not sure about the 'by' bit.).
'beak'+'er'='BEAKER'
Can you help me to learn more?
(Other definitions for beaker that I've seen before include "Open glass, straight with lip, used in laboratory" , "Tall cup or tumbler" , "Cup with a wide mouth" , "Flatbottomed drinking cup" , "Plastic cup without a handle" .)