desultory
adjective formal uk/ˈdes.əl.tər.i/ us/ˈdes.əl.tɔːr.i/
漫无目的的，随意的；无计划的
without a clear plan or purpose and showing little effort or interest
She made a desultory attempt at conversation. 她只是随意聊聊而已。
He wandered around, cleaning up in a desultory way. 他四下走走，心不在焉地收拾收拾。