The word "engrossed" refers to the hand-signed copy of the Declaration.
The image below is the most common image of the Declaration of Independence. It reproduces the version of the Declaration as engraved and printed by Willim J. Stone (1798-1865) in the year 1823.
Many people mistakenly believe that this image is, in fact, taken from the official, "engrossed" parchment copy which was signed by all of the delegates to the Continental Congress, but it was not. The engraver of this version was not even born at the time that the Declaration was adopted.
The official, engrossed parchment copy of the Declaration of Independence is maintained in the National Archives, and has never been photographed or reproduced by any means.