Small amount in moieties oddly (4)
I believe the answer is:
mite
'small amount' is the definition.
'mite' can be an answer for 'amount' (mite is a kind of amount). I am not certain of the 'small' bit.
'moieties oddly' is the wordplay.
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
The alternating letters of 'moieties' are 'MITE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for mite that I've seen before include "Tiny creature found in food" , "Arachnid; small child" , "Little chap" , "Old piece" , "Very small creature or child" .)