| Idiom | Meaning | Example | 
| snowball | 
grow, become bigger, spread to other people
 | 
Among students, discontent can snowball. It can spread rapidly.
 | 
| snowbirds | 
Canadians who go south for the winter
 | 
It's November, and the snowbirds  are leaving Alberta for Arizona.
 | 
| snug as a bug in a rug | 
warm and comfortable, cocoon
 | 
In this nice apartment, you'll be snug as a bug in a rug.
 | 
| so and so | 
a person you dislike, a name you forget
 | 
Who invited that so and so to the party? I don't like him!
 | 
| so far, so good | 
doing fine this far, good this far
 | 
After I had read one page,  she said, "So far, so good."
 | 
| so help me | 
I will need help to stop, I will need help if I do it
 | 
If that dog barks tonight, so help me, I'm going to get the shotgun!
 | 
| so long | 
goodbye, see you later
 | 
So long, my friends. I have to leave you now.
 | 
| so much as | 
this much will anger me, very little will anger me
 | 
If that cat so much as touches the baby, I'll tie up its tail!
 | 
| so quiet you can hear a pin drop | 
very quiet, very still
 | 
The teacher said, "Class, try to be so quiet you can hear a pin drop."
 | 
| so small you could barely swing a cat | 
very small room, narrow room, pokey
 | 
The bedroom was so small you could barely swing a cat in it.
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