Deacon

v. t.
  1. To read aloud each line of (a psalm or hymn) before singing it, -- usually with off.
  2. With humorous reference to hypocritical posing: To pack (fruit or vegetables) with the finest specimens on top; to alter slyly the boundaries of (land); to adulterate or doctor (an article to be sold), etc.

The expression is derived from a former custom in the Congregational churches of New England. It was part of the office of a deacon to read aloud the psalm given out, one line at a time, the congregation singing each line as soon as read; -- called, also, lining out the psalm.