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 “I” and contains 9 letters.
Definition: Pertaining to, having the nature of, or making, isocheims; as, an isocheimal line; an isocheimal chart.
It ends with “L”.
Clue 1 of 4 is visible.
Another word