1.
broad daylight, middle of the day
The brightest part of the day, emphasizing that it is clearly daytime with full sunlight.
真っ昼間から寝ている。
They're sleeping in broad daylight.
真っ昼間にそんなことをするなんて。
To do such a thing in broad daylight!
真っ昼間の繁華街で事件が起きた。
An incident occurred in the busy downtown area in broad daylight.
USAGE NOTE:
真っ昼間 often carries a nuance of surprise or criticism when used with actions that would normally occur at night or in private. The emphasis on 'broad daylight' suggests the action is inappropriate or unusual for that time.
VARIANT:
昼間 is the neutral term for 'daytime,' while 真っ昼間 emphasizes 'right in the middle of the day.'