cumbrous

From Late Middle English combrous (“causing obstruction; clumsy; obstructed; bothersome, difficult; burdensome, onerous; serious; causing trouble, troublesome; dangerous; immoral; unjust, wrongful; upset”) [and other forms], from komber, kumbre (“distress; destruction”) + -ous (suffix forming adjectives). The English word is analysable as cumber + -ous.