The buildup of oils, particles, hair and dirt on and underneath overutilized and uncleaned computer keyboard keys, mice and other human interfaceperipherals.
a cross between scrummy - (scrumptious and yummy) and delicious - can be referring to a wide variety of things including: a sexy or hot person, some delicious item of food, anything that although may not be edible; looks good, or even any such item
person: that food i ate for lunch was scrummiumptious
lady 1: that manover there looks so scrummiumptious i could just eat him up
lady 2: oh girl! you are so right!