filfil filius filli- fillis firlls firlus fislis fissi- flisks fluffs fluris flurri frills frisii frisks friuli fulfil furfur furrfu fusils ikkiss ilkufi illful irkful isurus kiffis kiisli kikiki kikkik kikkli kilifi kilkis kirill kiriri kiriru kirkuk kirkus kiruri kissui kisuki kluski krisis kuklik kuklis kukris kukuis kukuli kukuri kulfis kuliki kulilu kullur kululu kurils kurisu kurkul kuruki kururu kuskus kussir kuusik lifful lifull lilius lillis lilliu liluri liulis lufful lukulu lullus lurulu lusuku rififi riklis rilski ruffus rukkus russki russus ruukki siiiii sikulu silili silius silki sillik silluk siriri sirius sirris sirsir sisisi sisulu skiffs skills skirls skrill skruff skrull skulks skulls skulsk sliski sluffs srulik sssfrs sufli sukkur sulfur suliki sulili surful surili surkis surkul suslik susuki susulu susurr suuksu u-kiss ulfuls urkulu usiris ussuri