noun, na-adjective
Archaic noun/adjectival noun. In modern Japanese, this meaning survives almost exclusively in the adverb 正に (まさに).
See also: 正に
「正に」は、古い「正」の連用形に助詞「に」が付いた形だ。
「正に」 is a form where the particle に attaches to the continuative form of the old word 正.
The historical derivation is uncertain; the kanji 正 is conventionally associated with the meaning 'correct' or 'exact'.