adjective

of, resembling, or characteristic of an elephant or elephants, especially in being large, clumsy, or awkward.

there was an elephantine thud from the bathroom

enormous,huge,great,massive,giant,immense,tremendous,colossal,mammoth,gargantuan,vast,prodigious,gigantic,monumental,stupendous,titanic,monstrous,very big,very large,bulky,heavy,weighty,ponderous,lumbering,clumsy,laborious,jumbo,hulking,whopping,whopping great,thumping,thumping great,humongous,monster,almighty,dirty great,socking great,whacking,whacking great,ginormous