1. A greeting given to new employee upon joining a company. A: "Tom, this is Janet. She's our new project manager." B: "It's great to finally meet you in person. Welcome aboard!"
2. To welcome someone who has just joined a company. In this usage, a noun or pronoun can be used between "welcome" and "aboard." I'd like you all to join me in welcoming aboard our new VP of sales, Sarah Thompson! Everyone in the office made a point of stopping by my desk throughout the day to welcome me aboard.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
Fig. Welcome to employment at our company. (See also on board. Invariably said in greeting to a new employee.) Glad to meet you. Welcome aboard.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.