des ‧ ul ‧ to ‧ ry /ˈdes ə lt ə ri, ˈdez- $ -tɔːri/ BrE AmE adjective formal
[ Date: 1500-1600 ; Language: Latin ; Origin: desultorius , from desilire 'to jump down' ]
done without any particular plan or purpose:
They talked briefly in a desultory manner.
—desultorily /ˈdes ə lt ə rəli, ˈdes ə lt ə rɪli, ˈdez- $ -tɔːrəli/ adverb