"grass sb up" in German to grass sb. up jdn. verpfeifen hochgehen lassen Detailed translations for "grass sb up" to grass sb. up to grass sb. up(also: to squeal, to shit on, to fink, to rat on sb.) jdn. verpfeifen to grass sb. up(also: to peach on sb., to grass on sb.) hochgehen lassen{transitive verb}