Nauseous, as we say, intermittently, so back to work (7)
I believe the answer is:
seasick
'nauseous' is the definition.
(thesaurus)
'as we say intermittently so back to work' is the wordplay.
'intermittently' indicates alternate letters.
'so' becomes 'sic' ('sic' is 'so' in Latin).
'back to' indicates one should take the final letters.
The final letter of 'work' is 'k'.
'as'+'we'+'say'='aswesay'
The alternate letters of 'aswesay' are 'sea'.
'sea'+'sic'+'k'='SEASICK'
(Other definitions for seasick that I've seen before include "Upset by ship's motion" , "Unwell on the ocean waves" , "Suffering from mal-de-mer" , "poorly, in the main" , "Suffering nausea on board" .)