Intangible 
See ‘ungraspable’
Donated by Ellen Ball

Intercept
To obstruct or prevent a process
Donated by Jayne Simpson

Interesting
A word commonly used when there is not very much to say about an artwork. Often used when a student's work is, in fact, very uninteresting. Always worth asking why a tutor finds the work interesting as this can often see them flounder for words, waffle or start (mis)quoting theory.
"erm....what is happening here is very interesting...."

"So you are working with autobiography/beauty/celebrity/Ai/Dali/minimalism/social media/leaning things against the wall/post-irony.....how interesting"
Donated by Andrew Bracey