abounding in mountains

a mountainous wilderness.

of the nature of a mountain.

resembling a mountain or mountains, as being very large and high

mountainous waves.

adjective

alpine , big , colossal , gigantic , highland , huge , mammoth , tall , towering , behemoth , brobdingnagian , bunyanesque , cyclopean , elephantine , enormous , gargantuan , gigantesque , herculean , heroic , immense , jumbo , massive , massy , mastodonic , mighty , monster , monstrous , monumental , prodigious , pythonic , stupendous , titanic , tremendous , vast