Totally sick after consuming sodium (2,3)
I believe the answer is:
in all
'totally' is the definition.
(I've seen this before)
'sick after consuming sodium' is the wordplay.
'sick' becomes 'ill' (similar in meaning).
'after consuming' indicates putting letters inside.
'sodium' becomes 'Na' (chemical symbol).
'ill' placed around 'na' is 'IN ALL'.
(Other definitions for in all that I've seen before include "Taken as a whole" , "Taking everything into account" , "Summarising" , "Altogether" , "Everything considered" .)