大昔|おおむかしoomukashi[3]nakadaka (mid-high)

1. noun, adverbancient times; prehistoric times; the distant past; a very long time ago
   人間にんげんは大昔おおむかしに道具どうぐの使用しようを覚おぼえた。↗

   Man learned early to use tools.

• Related古くふるくNeutralAdverb or noun meaning a long time ago, as in 「古くから伝わる」 or 「古くは」; 「大昔」 feels more remote and is a noun.
• Related昔はCasualColloquial, meaning in the past or formerly, as in 「昔はよかった」; not as far back as 「大昔」.
• Antonym現代げんだいNeutralThe present age, modern times — the opposite pole to the remote past of 「大昔」.
• Antonym最近さいきんNeutralRecently, these days — the opposite of the very distant past expressed by 「大昔」.

Plain 「昔」 covers the past in general; 「大昔」 reaches much further back, to a very long time ago or ancient times, as in 「大昔の人々」. In written or formal prose prefer 「太古」 or 「古く」. For recent times say 「最近」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. かなり遠とおい昔むかし。太古たいこ。往古おうこ。