Cumbersome

громо́здкий

gromózdkij

(not easily managed or handled; awkward)

грузный

gruznyj

(inert, lumbering, slow in movement)

затрудни́тельный

zatrudnítelʹnyj

(burdensome or hindering, as if a weight or drag; vexatious; cumbrous)

неудо́бный

neudóbnyj

(not easily managed or handled; awkward)

обремени́тельный

obremenítelʹnyj

(burdensome or hindering, as if a weight or drag; vexatious; cumbrous)

объёмистый

obʺjómistyj

(inert, lumbering, slow in movement)

объёмный

obʺjómnyj

(inert, lumbering, slow in movement)

проблематичный

problematičnyj

(hard, difficult, demanding to handle)

сло́жный

slóžnyj

(hard, difficult, demanding to handle)

тя́гостный

tjágostnyj

(burdensome or hindering, as if a weight or drag; vexatious; cumbrous)