vobiscum

From vōbīs (“you”) +‎ -cum (“with”).

Cicero offered an amusing folk-etymology to the effect that the opposite order cum nōbīs was avoided because it would sound 'obscene', that is, a bit like cunnō bis 'twice by the cunt'. (Final /m/ can assimilate to a following consonant.)

• (Classical) IPA^(key): /u̯oːˈbiːs.kum/, [u̯oːˈbiːs̠kʊ̃ˑ]
• (modern Italianate Ecclesiastical) IPA^(key): /voˈbis.kum/, [voˈbiskum]

vōbīscum (not comparable)

1. with you (plural)

   Pax vobiscum

   Peace be with you.

   Dominus vobiscum

   The Lord be with you.

• Vulgar Latin: vōscum (see there for further descendants)

• vobiscum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• vobiscum in Georges, Karl Ernst, Georges, Heinrich (1913–1918) Ausführliches lateinisch-deutsches Handwörterbuch, 8th edition, volume 2, Hahnsche Buchhandlung