approximate
"Approximate" is a useful word with two main forms: an adjective and a verb. As an adjective, it describes something that is close to the real value but not exactly right. As a verb, it means to come close to something or to make a rough estimate. It appears often in academic, scientific, and everyday contexts.
When you approximate something, you get very close to it — in value, appearance, or quality — without being exactly the same. Imagine you are trying to copy a colour but you don't have the exact paint, so you mix colours to get as close as possible. That is approximating.
science, technology, academic writing · Modern, common in formal and technical contexts
The simulation approximates real-world conditions as closely as possible.
Her accent approximates a native speaker's, but you can still notice a slight difference.
You can also use 'approximate' to mean making a rough calculation or guess. Instead of working out the exact number, you approximate — you find a number that is close enough to be useful.
everyday language, business, science · Modern, widely used
We approximated the number of attendees at around 200.
The engineer approximated the weight of the structure before doing the full calculation.