セーフ

セーフ is a loanword from English "safe," originally a baseball term but now widely used in everyday Japanese.

BASEBALL USAGE:

• セーフ！: Safe! (umpire's call)
• アウト: Out (opposite call)
• セーフになる: to be called safe

EXTENDED USAGE:

Beyond baseball, セーフ is used colloquially to mean "OK," "acceptable," or "within bounds":

• ぎりぎりセーフ: just barely safe/acceptable
• まだセーフだ: it's still OK
• セーフ圏内(けんない): within the safe zone

CONTRAST:

• セーフ: safe, acceptable, within limits
• アウト: out, not acceptable, over the line

USAGE:
The extended sense is very common in casual conversation. For example, arriving just before a deadline: ぎりぎりセーフだった！ (I just barely made it!).