ditching. It usually applies to ditching school but it doesn't have to.
Use of the past tense is okay too, for example sloffed.
We went sloffing today during fourth period.
I sloffed it during the chemistry test because i didn't study.
I really wanted to go to the beach today but i couldn't because i had to work and i didn't feel like sloffing.
"Slof" is an abbreviation for "Shit load of fuck".
It is used to emphasize rage, similar to "Fuck" but more intense.
Person A: yo, your Ex, betty is going out with that guy you hate
Person B: What a Slof!