The Collaborative International Dictionary of English v.0.48:

obsecrate \ob"se*crate\ ([o^]b"s[-e]*kr[=a]t), v. t. [imp. & p.
   p. obsecrated (ocr/b"s[-e]*kr[=a]`t[e^]d); p. pr. & vb. n.
   obsecrating.] [L. obsecratus, p. p. of obsecrare, prop., to
   ask on religious grounds; ob (see Ob-) + sacrare to declare
   as sacred, from sacer sacred.]
   To beseech; to supplicate; to implore. [R.]. --Cockerman.
   [1913 Webster]