Poisonous type without delay drops second article (3)
I believe the answer is:
asp
'poisonous type' is the definition.
(I've seen this before)
'without delay drops second article' is the wordplay.
I cannot really see how this works, but
'second' could be 's' (common abbreviation) and 's' is located in the answer.
'article' could be 'a' (the indefinite article in English) and 'a' is found in the answer.
A single letter 'p' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for asp that I've seen before include "Slithery thing" , "Joe Blake is Australian species" , "It proved deadly for Cleopatra" , "Serpent" , "Egyptian cobra" .)