Sentence:  When culprit reason truant plays, / And wanders forth in fancy's maze, / Thy random shafts may please a-while, / And raise the <WSD>unreflecting</WSD> smile, / But soon as absent sense returns, / Our cheek with indignation burns, 
Meaning of the word marked with <WSD> tags:  ("of a person") Not giving reflection or thought to one's actions, words, conclusions, etc.; ("of an action, statement, conclusion, etc.") done without reflection or thought.