unconcerning

From un- +‎ concerning.

unconcerning (comparative more unconcerning, superlative most unconcerning)

1. (obsolete) Not affecting or interesting; insignificant.
   • 1722 (date written), Richard Steele, “468. To Mr. [William] Congreve”, in John Nichols, editor, The Epistolary Correspondence of Sir Richard Steele; including His Familiar Letters to His Wife and Daughters; […], volume II, London: […] John Nichols and Son, […]; and sold by Messrs. Longman, Hurst, Rees, and Orme, […], published 1809, →OCLC, page 610:

     I will not, therefore, busy myself about "the unconcerning parts of knowledge; but be contented, like a reader of plain sense, without politeness;" […]

2. Not concerning.

• “unconcerning”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.