lacking in consistency, constancy, or visible order, disconnected; fitful: desultory conversation.
2.
digressing from or unconnected with the main subject; random: a desultory remark.
Origin: 1575–85; < Latin dēsultōrius pertaining to a dēsultor (a circus rider who jumps from one horse to another), equivalent to dēsul-, variant stem of dēsilīre to jump down (dē-de- + -silīre, combining form of salīre to leap) + -tōrius-tory1