English English Dictionary
- under the weather in English:
1. 
slightly ill
English word "under the weather"(slightly ill) occurs in sets:
(© Pearson 2016 SOA2) UNIT 6 TRENDS (WORDLIST)2. 
not feeling very well
English word "under the weather"(not feeling very well) occurs in sets:
Sprawdzian 2A i 2BLesson 3 (25.11.2019)
3. 
ill
I'm ill.
I’ll call them tomorrow when I return home.
I was ill, otherwise I would have attended the meeting.
If he continues drinking too much, he will fall ill sooner or later.
This morning I got a telegram from home saying that my father had been suddenly taken ill.
Tomorrow I’ll go out with friends after having lunch.
My father saw that the letters were not in Yun’s handwriting, and asked me “Is your wife ill?”
Is Kim Jong ill or is Kim Jong okay?
Ill news comes apace.
It was the midnight of Friday, 13th; nothing of ill omen was apparent.
As our father got ill, we had to live on a small income.
I’ll give you that article.
The boy made believe he was too ill to go to school.
I think putting thieves to death is not lawful; and it is plain and obvious that it is absurd and of ill consequence to the commonwealth that a thief and a murderer should be equally punished.
What if you make yourself ill? An unbalanced diet leads to all kinds of sicknesses.
feeling a little sick or gloomy 
a little bit sick 
feeling sick 
feeling tired or sick 