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
1580s, "skipping about," from L. desultorius, adj. form of desultur "hasty, casual, superficial," lit. noun meaning "a rider in the circus who jumped from one horse to another while they are in gallop," from desul-, stem of desilire "jump down," from de- "down" + salire "to jump, leap" (see