Petty Officer on vessel suppresses extreme ire while putting together bouquets (6)
I believe the answer is:
posies
'bouquets' is the definition.
('posy' can be a synonym of 'bouquet')
'petty officer on vessel suppresses extreme ire' is the wordplay.
'petty officer' becomes 'po' (naval abbreviation).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'vessel' becomes 'SS' (prefix in ship names eg SS Great Britain).
'suppresses' is an insertion indicator.
'extreme' says to hollow out the word (remove centre letters).
'ire' with its middle removed is 'ie'.
'ss' going around 'ie' is 'sies'.
'po'+'sies'='POSIES'
'while putting together' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for posies that I've seen before include "Nosegays" , "Small bunches of flowers (a pocketful?)" , "Poises with bunches of flowers" , "'Corsages, small bouquets (6)'" , "Sprays" .)