"Welcome abroad" [closed]
Solution 1:
The phrase they were trying to use was almost certainly "welcome aboard." The greeting used to be used when someone boarded a ship, but now it's used more generally to welcome someone to a company, club, or team.
If you've seen "welcome abroad " multiple times, it's because it is an easy typographical mistake to make when typing too quickly. Spellcheckers won't catch it, because it's a real word and as far as the computer can tell, it's properly used.
It's possible that your Americanized friend's usage was not a typo, but a play on words, since you are both "abroad." If it was intentional, it's actually pretty clever, and to me it seems to suggest camaraderie rather than trying to belittle you.