noun

an impediment or burden.

the horse raised its hind leg as if to rid itself of an encumbrance

hindrance,obstruction,obstacle,impediment,restraint,constraint,handicap,inconvenience,nuisance,disadvantage,drawback,cumber,responsibility,obligation,liability,imposition,burden,weight,load,tax,stress,strain,pressure,trouble,worry,millstone,albatross,cross to bear,trammel