be on the sick —(coll.) be on sick list; receive sickness benefit:
- Dad used to be on the sick for a long time and couldn’t work.
be sick—
1. be unwell; be affected by illness:
- When she was sick he wanted her to get the best doctor.
2. (have an inclination to) vomit:
- “Ouch!” said Joss and looked as if she would be sick again.