Hastily wrote long passage, making a drug into something that might be boring (8)
I believe the answer is:
scrawled
'hastily wrote' is the definition.
'scrawled' can be an answer for 'wrote' (scrawling is a kind of writing). I'm unsure of the 'hastily' bit.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scrawled that I've seen before include "Wrote carelessly in bad handwriting" , "Wrote carelessly with red claws" .)