Meriweather was penalized for hitting a defenseless receiver in the head-and-neck area when he struck Smith in the second quarter during the Ravens' 23-17 victory. Smith was unhurt on the play.
Meriweather also legally hit Ravens running back Bernard Pierce in the head, causing a concussion and forcing him out of the game.
The violation of unnecessary-roughness rules regarding hits to defenseless players and impermissible use of the helmet is Meriweather's sixth in his career. He will lose two game checks, costing him $100,588 of his $855,00 base salary.
The punishment was upheld by appeals officer Ted Cottrell and imposed by NFL executive vice president of football operations Troy Vincent.
"On the play in question, Meriweather delivered a forceful blow to the head and neck area of a defenseless receiver with no attempt to wrap up or make a conventional tackle of this player," Vincent said in a statement.
Last year, Meriweather was suspended one game for illegal hits on Chicago Bears wide receivers Brandon Marshall and Alshon Jeffery.
While playing for the New England Patriots in 2010, Meriweather was fined $50,000 for an illegal hit on former Ravens tight end Todd Heap in which he launched himself into the air to deliver a crushing blow to Heap's chin.