Shaky bloke allows in one small needle (7)
I believe the answer is:
obelisk
'one small needle' is the definition.
'obelisk' can be an answer for 'needle' (I've seen this before). I'm unsure of the 'one small' bit.
'shaky bloke allows in' is the wordplay.
'shaky' indicates an anagram.
'allows' becomes 'is' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'in' is an insertion indicator.
'bloke' is an anagram of 'obelk'.
'obelk' enclosing 'is' is 'OBELISK'.
Can you help me to learn more?
(Other definitions for obelisk that I've seen before include "Tapering square stone monument" , "Stone "needle"" , "Kind of monument, tall sloping pillar" , "Ancient Egyptian monument" , "Tapering square pillar" .)