1Pitch-dark or pitch-black — describing a place with absolutely no light, completely dark.
停電で家の中が真っ暗になった。
A power outage plunged the house into pitch darkness.
夜道は街灯が少なくて真っ暗だ。
The road at night is pitch-black because there are so few streetlights.
カーテンを閉めたら部屋が真っ暗になった。
When I closed the curtains, the room went completely dark.
トンネルに入ると一瞬、目の前が真っ暗になった。
The moment we entered the tunnel, everything in front of me went pitch-black.
2Figuratively bleak or hopeless — describing a future or outlook with no hope in sight.
会社の業績が悪く、この先は真っ暗だと噂されている。
The company's performance is poor, and rumor has it the future looks bleak.
借金が重なって生活は真っ暗になった。
With debts piling up, life became utterly hopeless.