Thoughtless Thought"less, adv. 1. Lacking thought; careless; inconsiderate; rash; as, a thoughtless person, or act. [1913 Webster]

2. Giddy; gay; dissipated. [R.] --Johnson. [1913 Webster]

3. Deficient in reasoning power; stupid; dull. [1913 Webster]

Thoughtless as monarch oaks that shade the plain. --Dryden. [1913 Webster] -- {Thought"less*ly}, adv. -- {Thought"less*ness}, n. [1913 Webster]

The Collaborative International Dictionary of English. 2000.