To eliminate halftone dots or fine lines due to overexposure during camera work or platemaking. The lost copy is said to have dropped out. Found on http://www.e-printing.co.uk/glossary.htm
A patient enrolled in a clinical trial who is either unwilling or unable to return to the study clinic for regular follow-up visits. Found on http://www.virology.net/ATVGlossary.html
the way play is re-started, using a drop-kick, after the defending side has touched the ball down behind its own try-line or when the ball has gone out over the dead-ball line. Found on https://www.encyclo.co.uk/local/21640