awkward in movement or action; without skill or grace:
He is very clumsy and is always breaking things.
awkwardly done or made; unwieldy; ill-contrived:
He made a clumsy, embarrassed apology.
1590-1600;clums benumbed with cold (now obsolete) + -y1; akin to Middle Englishclumsen to be stiff with cold, dialectal Swedishklumsig benumbed, awkward, klums numbskull, Old Norseklumsa lockjaw. See clam2