As with an upskirt, the act of looking up one's kilt to obtain sexual gratification.
Bill blushed as he knew Frank was staring at his upkilt during the bagpipe concert.
by bethink March 13, 2006
The Scottish equivalent to "upskirt", but they wear kilts, not skirts.
"Yo did you see that dude's upkilt?" "Yea ma nigga he had some nasty old balls!"
by Hollaback1212 January 12, 2009