adj.红字的,用红字表示的;
例句:
I'd call that a red-letter day for any canine unit.
这些对于任何警犬来说都是大的收获.
It was a red-letter day for me when my son came home.
我儿子回家的那天对我来说真是个大喜的日子.
This is a red-letter occasion.
这是一件值得纪念的事.