“Worship” “Liturgy” “Service(s)” “Eucharist” “Mass” “Gathering” “Church” “Meeting” – these are some of the words that Christians use to describe their Sunday morning experience. While none are terrible, some are preferred by some tribes. Our own Lutheran tribe has a preference toward “Service,” specifically “Divine Service” due to the German word “Gottesdienst” which literally means “God’s service [toward humans]”. However, the sense of service gets watered down in the normal English usage which normally makes it out to be “church’s service [to those gathered]”, the idea being that the church is the “provider of religious services”. 
The Old English derivative, “worship” is the most literalistically Biblical of the choices that we have. Worship is the English translation for a whole mess of Greek and Hebrew words that all have the sense of “ascribing glory to God” (i.e Psalm 29, 96, etc). When you read the Bible, you will find the word “worship” as the thing that defines the experience that we call…well…all of those words in the first sentence above. The etymology of the word means “worth ship,” or as I put in a sermon somewhat recently “worth the trip”. However, it fails in that it really focuses on the human side of the equation, placing everything on the experience of the human ascribing glory to God without saying what moved us to ascribe that in the first place (God’s grace, mercy, power, etc).
Speaking of Greek and Hebrew words, our word “liturgy” is a cognate of the Greek word “leitourgia” which is a compound word of two parts: “laos” (people) and “ergon” (work). Like “worship”, this word really only talks about the human experience of worship, the “work” of paying attention, confessing things along with other people, showing up, wrangling your children in their seats, resisting the temptation to check your Instagram account, etc.
Some of our names for [uh, whatever you call Sunday] deal more specifically with what we’re receiving, especially sacramentally. “Eucharist” is one of these. While technically “eucharist” means “thanksgiving,” it became shorthand for “Lord’s Supper” as early as the first century A.D, alluding to Jesus’ words of institution of the Sacrament of the Altar, “…and when He had given thanks…”. Somewhat similarly, the word “mass” became shorthand for the Lord’s Supper due to the uninitiated being sent or “missa”‘ed before the Lord’s Supper began. These names, however, downplay the role of the reading and explication of God’s Word which is unfortunate and something that the Reformers reacted against.
This Sunday, our reading of Hebrews is going to include the warning not to “neglect to meet together”, which forms another grouping of names which tend to be newer and more American including “Gathering” and “Sunday meetin'”. These words bring the communal reality of the Sunday experience to the forefront (which you might say is ironic given the hyper-individualist nature of American Sunday experiences). They also (at least historically) have the notion of God’s meeting humans, as in the “Tent of Meeting” where Moses would speak with God face to face in the first five books of the Bible.
Lastly, the one that we probably use most often is “church”. The word “church” is the translation of the Greek word “ekklesia” which means “called out”. It has its roots in the idea of a town crier or troubadour gathering everyone to hear the news. In its original sense, it has this gorgeous non-building-specific sense of a people who are called together by a message of Gospel. The “ekklesia” are what we would call the “audience”, the hearers of the good news. However today, unfortunately, this word has less to do with the message or the people and is simply used as referent to the building. Sad face.
So what do you call it? Here at University Lutheran, we use worship for the overall experience. We also note in the bulletin that there are two “services”, the service of the word and the service of the sacrament. But if anything, I would be interested what else we could call what we do on Sunday morning that would be clearer to someone who has no earthly idea what a “service” or “liturgy” or “eucharist” or “gottesdienst” is supposed to imply. The best I’ve come up with is “delivery,” but even that falls short in some places.
Why does it even matter what we call it, though? The issue of language is this – it helps us communicate. If we’re just naming stuff, then we can call Sunday morning “SparklyDivinityForgivenessFest” or maybe something fancier in Latin or Greek or Hebrew or Sanskrit or something. But if we’re communicating, then we have to know who we’re talking to, and we have to….well…talk to them. I just gave you a bunch of words to describe what you could invite someone to on Sunday morning. I honestly don’t care which you use or don’t use. Just tell them to come along with you, meet Jesus, get forgiveness and community, and that they get to come up with a name for the experience after they are done.