pre-noun adjectival
strange; odd; unusual; peculiar
Dated pre-noun adjectival meaning 'strange' or 'unusual'. It is rarely used in modern Japanese outside of literary or historical contexts; the more common word is 異様 (いよう) or 変 (へん).
異なことを言うものだ。
What a strange thing to say.
異な風習がこの村には残っている。
Unusual customs remain in this village.
異様 is the modern, common word for 'strange' or 'weird', while 異な is dated and literary.
変 is a casual, everyday word for 'strange' or 'odd', whereas 異な is formal and archaic.
The word is derived from classical Japanese. The exact historical derivation is uncertain; it is a pre-noun adjectival form related to the concept of 'difference' or 'strangeness'.