It's card, perhaps, but very strong (7)
I believe the answer is:
drastic
'very strong' is the definition.
'drastic' can be an answer for 'strong' (similar in meaning). I'm unsure of the 'very' bit.
'it's card perhaps' is the wordplay.
'perhaps' is an anagram indicator.
'its'+'card'='itscard'
'itscard' with letters rearranged gives 'DRASTIC'.
'but' is the link.
Can you help me to learn more?
(Other definitions for drastic that I've seen before include "Severe and far-reaching" , "Desperate" , "Extreme - forceful" , "Extremely severe" , "Having strong effect" .)