inofficious adjective3 •(no longer used) Indifferent to obligation or duty.Vp thou tame River, vvake; / And from the liquid limbes this slumber shake: / Thou drovvn'st thy selfe in inofficious sleepe; / And these thy sluggish vvaters seeme to creepe, / Rather than flovv. — 1604 •(no longer used) Contrary to one's natural obligation or duty, as of a testament by which a child is unjustly deprived of inheritance. •(no longer used) Not officious; not civil or attentive. formsmore inofficious · most inofficious