· spectacular
· stereotyped
· substantial
· sympathetic
The shape you're looking for is "seesaw." It has 11 letters, possesses at least one line of symmetry, and starts with the letter "s." A seesaw can be symmetrical along its central axis.
suha
scallop
Swiss.
processes
Spaceship
samsung
yes, smoothly has 8 letters and starts with s
Roast
Kansas city Kansas
Escalade
isogloss