The word "Tehilim" stems from the word for a praise, "Tehilah." However, (1) it is difficult to pronounce the "Heh" when it is not at the beginning of a word and therefore it is commonly dropped. For example, the name "Rebbi Yehudah" is spelled in many places "Rebbi Yudah," such as in the Tosefta (and "Rebbi Yudan") in the Yerushalmi. This was probably the colloquial pronunciation of his name -- and of Tehilim/Tilim -- because of this difficulty in annunciating the "Heh" in the middle of a word. (2) In Aramaic the word for Tehilim is Tilin or Tilei (see Pesachim 117a) so it was natural that the Hebrew word would be influenced by the Aramaic-speaking Chachamim and be pronounced in a similar way to Aramaic. In one sentence in the Yerushalmi (Bava Basra 1:5) the two words "Tilim" and "Tilin" are used interchangable, proving that the Aramaic influence is behind the word Tilim.

To this day, in many communities the word "Tilim" is used, due both to the Talmudic precedent and probably because it is easier to pronounce.

Yoel Domb