ת The twenty-second letter of the Heb. alphabet. The name of the letter, תָּו or תָּיו (‘Tav’, also ‘Taw’), means ‘sign’, ‘mark’; so called in allusion to the ancient form of this letter. In PBH it has the numerical value of four hundred. In the Sem. languages ת alternates with ד, ט and שׁ (see the introductory entries to these letters). ת often appears as the first radical in secondary bases enlarged from primary ones; see תאב ᴵ, תוה, תחל, possibly also תהל (supposed to be the base of תָּהֳלָה). The ת in these cases is either traceable to the ת of the conjugation הִתְפַּעֵל, or is originally identical with the subst. pref. תּ◌ (see תַּ◌, תִּ◌, תּוֹ◌). See תבע.