Dangerous load carried under end of arch (7)
I believe the answer is:
harmful
'dangerous' is the definition.
('harmful' can be similar in meaning to 'dangerous')
'load carried under end of arch' is the wordplay.
'load carried' becomes 'armful' (I can't justify this - if you can you should believe this answer much more).
'under' is a charade indicator (letters next to each other).
'end of' suggests the final letters.
The final letter of 'arch' is 'h'.
'armful' put after 'h' is 'HARMFUL'.
Can you help me to learn more?
(Other definitions for harmful that I've seen before include "Injurious" , "Noxious" , "Causing injury or damage, say poison or malice" , "Half rum (anag.)" , "Dangerous, damaging" .)