The simple blend of spam and crappy. Often used to describe something truly grody that is endorsed by a higher authority or the majority.
My high school yearbook was so spappy this year.
My sister is dating the spappiest guy, how can anyone like him?
A person with a flat, straight, style-less or flairless wet or wet-looking comb-over, the wet comb-over itself, an oily-haired comb-over, an oily haired comb-over with chunks of dandruff or other abnormal or unexpected particulate matter, or any feature of a person having said variations of the comb-over that reminds you of that person having said variations of the comb-over.
The hair of a 1920's era poor farmboy using too much pomade after not washing for 7 weeks; a person having a barber style cut from a 92 year old barber who learned his trade in the 1920's; a person who doesn't wash hair often (say, less than once every two weeks) and uses the same cheap, bendy black comb with embedded scalp flake chunks to comb their hair in a comb-over pattern, whether the comb-over technically is needed or not. "Gee, that guy's hair is really spappy."