So does anyone know what word is used in Latin?
Pascha - whence the PNN & adjective Pasc[h]al[is] & Pasc[h]asius (= “pertaining to Easter”) 
Rather interestingly, there is at least one “Babylon connection” to names of Popes:
is one of several Popes of Syrian origin. Sisinnu - not to be confused with Sissinnu - is a name for the constellation known to us as Virgo. (Sissinnu is a name for the constellation known to us as Coma Berenices, “Berenice’s Hair”). The termination -ius in Latin = “belonging to X”. So Dionysius, Liberius, Eleutherius, Mavortius, etc. = belonging to Dionysius, Liber, Eleutherus, Mars, etc.
This is a
linguistic connection - it does not show that there is connection between
what is named: it is illegitimate to seize on the fact that someone is called Dionysius, & say, “that person is honoured as a Saint, but he is really named after the god Dionysius.” If these names proved a
religious connection as well as an
etymological derivation, the Apostle & the deacon Philip would both have to connected with Philip II of Macedon, merely because they all share a name. But etymological derivation of a name does not of itself provide any information as to why it is given: someone called John may be called after a Saint - or after his grandfather, without reference to any Saint whatever. Names formerly associated with other gods are capable of gaining new meanings & associations: another reason it is rash to jump to the conclusion that Christians have pre-Christian meanings & uses of names in mind when they use them.
Was Sisinnius called after the constellation ? It’s unlikely, because the name Sisinnu is Akkadian, & Akkadian had (from all other available evidence) died out centuries before Sisinnius became Bishop of Rome. Some Mesopotamian cults survived for many centuries, more or less disguised by other names or titles. Another possibility is that the name had become traditional in his family. It is impossible to be sure why he was named as he was, so it is impossible to use his (very interesting) name as evidence of the paganisation of Christian Rome. It is notable because of its Akkadian origin, which is what makes it a useful test of the possibility of connections between Christian Rome & pre-Christian Mesopotamia.
Some words have survived - saffron is from the place-name Azupiranu; Mediaeval Latin meschinus & its derivatives come from Akkadian mushkenum (a social class) & there are others. So there are not no linguistic (or other) connections with European languages. But, they have to be sought out - they are unobtrusive, & misidentifying the languages used in Mesopotamia leads to finding them where they don’t exist. We can turn the question back on the “Babylon-connectors”: what connection have these genuine Akkadian or Sumerian words with the words, or even the objects, or the ideas & doctrines, of Catholicism ? The burden of proof is on them, not on Catholics: for it is they and not Catholics who assert that “Catholicism is pagan”.
Are there connections between Catholicism & the pre-Christian world ? Certainly - but showing a connection is not enough if the idea is to use it to condemn (or praise) Catholicism. Connections are of many types: literacy was a Sumerian invention, but that fact is insufficient to show that literacy is evidence of worshipping Sumerian deities. Many of the connections between Roman Catholicism & Mesopotamia arw the result of their being linked by the culture/religion of the Bible: Israel had much in common with its neighbours (such as some of its ideas about kingship); the influence on the Church of passages & concepts reflecting such commonalties means that by having something in common with Israel, a culture outside Israel was influencing the Church. But influence is not the same as distortion - the “Babylon-connectors” seem to overlook this. Or, they seem to regard the Bible as constituting a zone free of all influence from outside - it acts as a “force-field”, which is impervious to all non-Israelite ideas that are not materially present in the Bible. This violates the incarnational principle, & it absolutises an object as an object,which is a contradiction of the sovereignty of grace.
I have some notes on Ishtar herself. Denying a connection between her name & that of Easter is not enough - the person making the connection can always say, “But how can you show there is no connection ?” So some details about her may be use to explain why the connector is on weak ground.
