Or, 'frontlets' (Ibn Janach, Radak, s.v. Tataf; cf. Targum on 2 Samuel 1:10; Shabbath 57a,b; Tosafoth, Menachoth 34b; Ramban). Totafoth in Hebrew. The Targum renders this word as Tefillin, having the connotation of prayer, judgment and testimony (Tosafoth, Menachoth 34b, s.v. LeTotafoth). In Greek they were also known as phylacteries, from the root phylassin, meaning to watch or to guard. (See Josephus, Antiquities 4:8:13 commentaries on Ezekiel 24:17).
According to Talmudic tradition, the word totafoth alludes to the four boxes in the head Tefillin, since tot in a Caspian dialect is two and foth or poth is two in African or Phrygian (see note on Genesis 10:2; Menachoth 34b). The word tot appears to be cognate to 'two,' and possibly also to the Latin totas, and hence the English 'total.' Poth is cognate to the Gothic bothe, the English 'both,' and the Sanscrit botto.
Significantly in ancient Egyptian, ftu or fot means four, while tot can denote a gathering, resemblance, divine, or hard leather. Hence, totafoth may have had the connotation of a fourfold amulet, made of leather, as the Tefillin indeed are. Others note that in Egyptian, tot or otat denotes the brain, where the head Tefillin are placed (Abarbanel).