Origin: L < non, not + obstans (gen. obstantis), prp. of obstare: see obstacle: from use in medieval legal clauses permitting to the king certain actions notwithstanding statutes to the contrary
See non obstante in American Heritage Dictionary 4
Origin: Middle English
Origin: , from Medieval Latin nōn obstante (aliquō statūtō in contrārium), notwithstanding (any statute to the contrary)
Origin: : Latin nōn, not
Origin: + Latin obstante
Origin: , ablative present participle of obstāre, to withstand.