William F. Buckley, Jr., Word of the Day:

Surreptitious

1. Done, made, or acquired by stealth

2. Acting or doing something clandestinely 

"It turned out that several of my coconspirators had fathers with similar prejudices, so that when our little syndicate was formed we all agreed that communications among ourselves on the subject of our surreptitious hobby would go out discreetly, lest they be intercepted."