A specialty coffee menu can read like a foreign language even to someone who drinks coffee daily, mostly because a lot of the vocabulary is borrowed directly from Italian espresso tradition and never fully translated. Here is a working glossary of the terms you are most likely to actually run into.
Ristretto is a "restricted" espresso shot, pulled with less water than a standard shot for the same amount of ground coffee, producing a smaller, more concentrated, and generally sweeter result since it stops extracting before the more bitter compounds come through as strongly. Lungo is the opposite, a "long" shot pulled with more water through the same amount of grounds, resulting in a larger, more diluted, and generally more bitter shot as extraction continues further. Lance Hedrick demonstrates the difference on camera, which lands better than a definition does.
Doppio simply means "double" and refers to a standard double shot of espresso, which has become the default single serving size at most specialty shops rather than a single shot, since a single shot alone is often considered too small to properly showcase a coffee's flavor.
Crema is the golden-brown foam layer that forms on top of a properly pulled espresso shot, created by carbon dioxide and oils being forced out of the coffee under pressure. It is often treated as a visual marker of a well-pulled, fresh shot, though crema thickness varies by bean and roast level too, so its absence is not automatically a sign of a mistake.
Single origin describes coffee sourced entirely from one country, region, or specific farm, letting you taste the character of that particular place rather than a deliberately balanced mix. A blend, by contrast, combines beans from multiple origins on purpose, usually to hit a specific, repeatable flavor profile.
Extraction refers to the process of pulling flavor compounds out of ground coffee using water, and "under-extracted" or "over-extracted" are the two most common ways a cup goes wrong, sour and thin versus bitter and harsh, respectively, covered in more depth in our espresso vs drip guide.
Body describes how heavy or thin a coffee feels in your mouth, independent of flavor or strength, a lighter-bodied coffee feels closer to tea, while a fuller-bodied one feels closer to whole milk. Acidity, in coffee-tasting language, does not mean sourness in a bad sense, it refers to a bright, lively quality, closer to the tartness in a green apple or citrus, that is generally considered a positive trait in a well-made light roast.
If a term comes up on a menu you visit that is not covered here, it is genuinely fine, and encouraged, to just ask. A shop that roasts its own beans, like Franken Coffee Bar + Roastery, will usually have staff happy to explain exactly what is behind any word on their board, and that conversation is often more useful than any glossary for actually connecting a term to a taste. Sprudge also runs a long series of short explainers on individual drink names, handy for the ones that keep tripping you up.