WordNet (r) 3.0 (2006):

kitchen police
    n 1: an enlisted person who is assigned to assist the cooks
         [syn: kitchen police, KP]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "kitchen police":
   KP, army, army group, battalion, battery, battle group, brigade,
   cadre, cohort, column, combat command, combat team, company, corps,
   detachment, detail, division, field army, field train, file,
   flying column, garrison, legion, maniple, organization, outfit,
   phalanx, platoon, posse, rank, regiment, section, squad, squadron,
   tactical unit, task force, train, troop, unit, wing