Just short of the donations required to bring in Oscar and Tesla (6)
I believe the answer is:
almost
'just' is the definition.
(thesaurus)
'of the donations required to bring in oscar and tesla' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'donations' could be 'alms' (I've seen this before) and 'alms' is present in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
'short' acts as a link.
Can you help me to learn more?
(Other definitions for almost that I've seen before include "Virtually" , "As good as" , "Slightly short of" , "Not entirely" , "practically" .)