Sanity comes from Latin sanitas ('health, soundness of mind'), from sanus ('healthy, sound'). The historical chain includes Latin sanitas and Latin sanus. The quoted older senses, "health, soundness of mind" and "healthy, sound", supply the semantic anchors for sanity. The formation is best read as borrowed: the word sanity carries its older form-history into a compact English lexical shape. In present English it is used as a noun, "the state of being sound in mind; reasonable and sensible judgment". Related English forms include sane, sanitary, and sanitize. The result is a noun whose etymology preserves both the older form and the later English specialization.