Progressive clue challenge

How quickly can you identify the hidden word?

Begin with a broad grammatical clue. Reveal more only when needed. Fewer clues and fewer wrong guesses produce a higher score.

100
It is used as an adjective.
It begins with “S” and contains 8 letters.
Definition: Adapted for forming slabs, or for dressing flat surfaces.
It ends with “G”.
Clue 1 of 4 is visible.
Another word