Twinning

Twinning (making a twin of) may have the following meanings:


 * In biology and agriculture, producing two offspring (i.e., twins) at a time, or having a tendency to do so;
 * City and town twinning;
 * eTwinning, a collaboration between schools in which two schools in different geographic locations are paired and communicate using the Internet;
 * Widening of a road by construction of another one next to it, with a median in between (Canadian English), upgrading the road into a (usually) four-lane dual carriageway (divided highway);
 * Crystal twinning in crystallography refers to intergrown crystal forms which display a twin boundary: Crystal habit;
 * "Twinning" is a jargon term in motion pictures for various special effects that allow to double (or multiply) the presence of the same actor or actress on screen;
 * "Twinning" is a jargon term in animation when two parts on opposite sides of a character's body are moving the same way.
 * "Twinning" is a concept in education in Malaysia, where private colleges offer programmes whereby the student does part of his degree course locally and part of it in an overseas institution tied to the college.