low spirits; lack of enthusiasm; unmotivated
Wasei-eigo from 'low tension'. Describes a person's mood or energy level being low, often in contrast to ハイテンション. Common in casual conversation.
from English low tension
See also: ハイテンション
I'm feeling low today, so I don't want to go anywhere.
low voltage; low tension (electrical)
Rare technical use in electrical engineering, directly from English 'low tension'. Not used in everyday Japanese.
He's always low-energy and doesn't talk much.
This circuit operates at low voltage.
Variant with interpunct; less common but still seen.
Wasei-eigo from English 'low tension'. In English, 'low tension' is primarily a technical term, but in Japanese it has taken on the meaning of low spirits or lack of enthusiasm.