What does "be late" mean?

To have one’s menstrual discharge late, implying successful nidation suspected.

What is a synonym for "be late"?

Common synonyms include: burn the midnight oil, miss the boat, oversleep, straggle.

verb, slang

verb, slang ·Uncommon ·College level

Verb

1
To have one’s menstrual discharge late, implying successful nidation suspected. colloquial