The word “vení” is a variation of the command VEN. In some Central America countries like Honduras, El Salvador and even in some areas of Costa Rica is common the “voseo”. That means that “vos” is used instead of “tú” and “veni” would be the command.
In Colombia, for example, the “voseo” is also the norm in some regions like El Valle, Cauca, etc.
Maybe that is the word the student heard, and yes, it does exist.