I'm assuming the previous meaning that was added was just a joke or sarcasm, if not then they don't actually know what they are talking about. Actual meaning is for someone who is obsessed with WW2 German military (Wehrmacht), a modification of the term Weeaboo which is someone non-Japanese who is obsessed with Japanese culture.
wehraboo הגייה עם משמעויות, מילים נרדפות, הפכים, תרגומים, משפטים ועוד