Yours, Etc.: Origins and Uses of 8 Sign-Offs
word-forming element meaning "above, over, beyond, before," from Latin supra "above, over, before, beyond," in supera (parte), literally "on the upper (side)," from old fem. ablative singular of superus (adj.) "above," related to super "above, over" (see super-).
Above; over; on top of: supracostal.
Greater than; transcending: supraliminal.