plural noun Judaism.
Origin of tefillin
Examples from the Web for tefillin
Some of the women had wrapped themselves in traditionally male religious garments like tallit and tefillin, and others had not.NYC Jews Pray In Solidarity With Women Of The Wall|Sigal Samuel|March 12, 2013|DAILY BEAST
These phylacteries (tefillin in Hebrew) are still used by orthodox Jewish men.
Word Origin and History for tefillin
1610s, from Rabbinical Hebrew t'phillim, plural of t'phillah "prayer."