Some sentence examples which use the word 'rarefy'
—_fy_, meaning to make, is found as a suffix in derivatives too numerous to mention; as, purify (to _make pure_), rarefy (to _make rare_), classify (to _make_ or put into a _class_), etc.
The markings, always spots and specks, the largest never exceeding 0·1 inch in diameter, are invariably most numerous towards the large end, where they are sometimes, though rarefy, slightly confluent.