Does the word voltage exist in academic engineering?
Yes, voltage is a technical word in English.
From Wordnik:
noun A measure of the difference in electric potential between two points in space, a material, or an electric circuit, expressed in volts.
In fact, Wikipedia even lists "electric tension" as a synonym, though I hadn't heard that before. Mostly it's referred to as voltage or potential difference.
Some other answers have noted that Electric Tension was used to describe a potential difference until the mid-20th century in England, but it went out of popularity.
Google’s Ngram shows that voltage is far more popular than Electric Tension ever was, though.
The water analogy of electricity was historically influential, both terms, "tension" and "current", were the result of this analogy.
In the early 1900s, "tension" was the standard technical term in English for electric potential. The B+ of a vacuum tube was called High Tension (HT), and a Cathode Ray Tube required "Extra-High Tension" (EHT) to operate. For some reasons, the word "tension" in English became obsolete in the middle of the 20th century (I cannot find a reference), and the term "voltage" became the standard technical term instead. Similarly, the old technical term for a "capacitor" was "condenser". A microphone that works by the change of capacitance was (and still is) called a "condenser microphone". In 1926, the term "condenser" was abandoned in English, but it took a generation or two to pick up the new term, fully replaced the old term around mid-20th century.
However, the translation of basic terms in electrical engineering to other languages was done long before this transition, so in many other languages, the technical term is still "tension" or "pressure", and a "capacitor" is still a "condenser".
The main reason seemed to be an effort to reduce the confusion between electrical engineering and mechanical engineering terms. Early 1900s was still the heyday of steam engines, and the confusion could be very real, and I fully understand the choice for "capacitor" over "condenser". But I think the choice "voltage", from a physical sense, is very unfortunate. Most physical quantities, as physical phenomena, have their own names independent from their units of measurement. When we talk about force as a phenomenon, we don't refer it as "newtonage", neither we use "wattage" for power.
$$\require{cancel}$$ \begin{array} {|l|l|l|l|} \hline \text{Phenomenon} &\text{Name} &\text{Unit} &\text{Numerical Name}\\ \hline \text{A push} &\text{force} &\text{newton} &\text{-}\\ \text{Flow of charge} &\text{current} &\text{ampere} &\text{amperage}\\ \text{Rate of work} &\text{power} &\text{watt} &\text{wattage} \\ \text{Electric Potential} &\cancel{tension} \text{voltage (!!)} &\text{volt} &\text{voltage (!!)} \\ \hline \end{array}
The introduction of "voltage" makes electric potential lost its own name, making it the only physical quantity named after its unit of measurement in English.
However, "voltage" is the standard term English, we have to follow it all along...
In the International System of Units (SI) and the corresponding International System of Quantities, as described in the international standards series ISO/IEC* 80000 Quantities and units, quantities are always independent of the unit in which they are expressed; therefore, a quantity name shall not reflect the name of any corresponding unit.
However, ISO 80000 Part 1 General as well as IEC 80000 Part 6 Electromagnetism note that the name “voltage” is commonly used in the English language and that this use is an exception from the principle that a quantity name should not refer to any name of unit. It is recommended to use the name “electric tension” wherever possible.
The same information can be found in the series IEC 60050 International Electrotechnical Vocabulary (IEV), especially IEC 60050-121.
* The International Organization for Standardization (ISO) collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.