Although tefillin is technically the plural form (the singular being tefillah), it is loosely used as a singular as well. The arm-tefillin, or shel yad, is placed on the upper arm, and the strap wrapped around the arm/hand, hand and fingers; while the head-tefillin, or shel rosh, is placed above the forehead.
Definition of declination. 1 : angular distance north or south from the celestial equator measured along a great circle passing through the celestial poles. 2 : a turning aside or swerving. 3 : deterioration moral declination. 4 : a bending downward : inclination.
The term magnetic deviation is sometimes used loosely to mean the same as magnetic declination, but more correctly it refers to the error in a compass reading induced by nearby metallic objects, such as on board a ship or aircraft.agnetic declination should not be confused with magnetic inclination, also known as magnetic dip, which is the angle that the Earth's magnetic field lines make with the downward side of the horizontal plane.