Break records with small humanitarian organisation (3,5)
I believe the answer is:
red cross
'humanitarian organisation' is the definition.
(I've seen this before)
'break records with small' is the wordplay.
'break' indicates an anagram.
'with' is an insertion indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'records' anagrammed gives 'redcros'.
'redcros' placed around 's' is 'RED-CROSS'.
(Other definitions for red cross that I've seen before include "International humanitarian organization" , "International organisation for treatment of wounded in war" , "Intl. relief agency" , "International organization that cares for victims of war" , "that brings relief!" .)