The adjective suggestive is useful when one thing indicates or hints at something else. Your constant yawning, for example, is suggestive of how tired you are.
Scientists and researchers often use the word suggestive to describe results that indicate a strong possibility of something without decisively proving it: "This is suggestive evidence of life on other planets." Sometimes, suggestive is used to describe something inappropriate or obscene: "Parents always think popular music's lyrics are too suggestive." This meaning came about in the late 1800's, more than two hundred years after suggestive first appeared in the language from the verb suggest.