Adjective cumbersome has 2 senses
- cumbersome, cumbrous - difficult to handle or use especially because of size or weight; "a cumbersome piece of machinery"; "cumbrous protective clothing"
Antonyms:  wieldy, manageable (indirect, via unwieldy)
 - awkward, clumsy, cumbersome, inapt, inept, ill-chosen - not elegant or graceful in expression; "an awkward prose style"; "a clumsy apology"; "his cumbersome writing style"; "if the rumor is true, can anything be more inept than to repeat it now?"
Antonym:  felicitous (indirect, via infelicitous)
 
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