I am looking for a word (or phrase), which is as short as possible (restriction is 12 letters) and has the meaning of
oral presentation (well, including the use of a beamer and visual presentation), given at an academic conference
"oral presentation" is too long, "talk" is quite short (But is this appropriate?), and "lecture" feels too formal. Just "presentation" does not work because this could also mean "poster presentation".
What is the usual term/word/phrase for this?
Talk is a completely appropriate academic term for an oral presentation, just as paper is for an article or a monograph, regardless of its simple sound. Naming the conference will reinforce the academic meaning of talk.
If you want to include more letters, you could use the term formal talk or, if true, invited talk.
Demonstration would be a good choice when it suits the content, but happens to have one letter too many for the purpose in question.
One of the most respected Physicists ever, Richard Feynman, is famous for his “talks”:
Many of his lectures and miscellaneous talks were turned into other books, including ... – Wikipedia
The word you might be looking for is lecturette.
He gave a lecturette on an interesting subject.
Presentation would also work, but would be a short presentation for your requirements.
short presentation
short lecture
short lesson
