Kept private or not revealed

• Beyond ordinary understanding
• Not openly made known
• Squirrel, at times
• The next to highest level of official classification for documents
• Not open or public
• Not expressed
• Having an import not apparent to the senses nor obvious to the intelligence
• Designed to elude detection

Wiktionary Word definitions in Wiktionary
n. (alternative spelling of secretor English)

WordNet Word definitions in WordNet
n. any of various organs that synthesize substances needed by the body and release it through ducts or directly into the bloodstream [syn: gland , secretory organ , secretor ]