Pregnant; knocked up. Means literally that "one" kid is "on the way" (will be born soon, and will consume every moment of your spare time with its endless whining). Not a good thing if you have a girlfriend/wife who is not the mother of the baby.
Synonyms for one on the way
On this page, you will find 30 slang terms related to one on the way. Some of the top words include: pregaz, Raceracy, late, POPPIN MOMA, preggers, and 25 more.