ubique

Ubique is ubi, "where", plus the generalising -que, so literally "wherever you like", hence "everywhere". Latin builds a neat set this way: quisque, "each", uterque, "both", plerique, "most". The -que here is not the "and" of arma virumque.

Keep three adverbs apart. Ubique is place where, "everywhere". Undique is place from which, "from all sides", and it is the one you want for an army being attacked. Passim is "here and there, scattered about", which is weaker than either. Ubique is regularly reinforced with a partitive genitive, ubique terrarum, "everywhere in the world", exactly like ubi gentium. English took ubiquity and ubiquitous from it, both of which arrived by way of theological argument about God being present in all places at once.