noun: the front of a leaf, the side that is to be read first
From Latin recto folio (right-hand leaf), from rectus (right). Ultimately from the Indo-European reg- (to move in a straight line, lead, or rule) that is also the source of regent, regime, direct, rectangle, erect, rectum, alert, source, surge, arrogate, abrogate, regent, and supererogatory.
Earliest documented use: 1789
In languages that are written left-to-right, such as English, recto is the right-hand page. In languages written right-to-left, such as Arabic, recto is the left-hand page. The other side is called verso.
Usage (from Wordsmith)
“The foot of the opening recto displays an unframed heraldic device: the royal arms of England.”
The Opicius Poems; Renaissance Quarterly (New York); Sep 2002.