sid·dur 
(sĭdər, -r′)
(sĭdər, -r′)n. pl. sid·du·rim (sĭ-drĭm, sĭ′d-rĭm)
A Jewish prayer book for everyday use.
[Mishnaic Hebrew siddûr, arrangement, from siddēr, to arrange, derived stem of sādar; see sdr in the Appendix of Semitic roots.]