Adams pushed New York Giants defensive end Justin Tuck in the back, sending him to the ground. Adams, through his agent Jordan Woy, told the league he thought the play was still alive. He also grabbed the face mask of defensive end Mathias Kiwanuka.
League spokesman Randall Liu said the fine was for unnecessary roughness, his fifth such infraction this season.
In a letter to Adams, NFL executive vice president of football operations Ray Anderson wrote: "Future infractions of the types you have committed may lead to increased disciplinary action up to and including suspension."
Adams already has been fined $25,000 for incidents in three other games this season, including $12,500 stemming from Dallas' first meeting with New York in Week 2, when Adams tripped Tuck.
As a repeat offender, and with a history of tangling with Tuck, there was thought that Adams could be forced to sit out a game.
Adams wasn't in the locker room when it was open to the media Wednesday.
After Sunday's game, Tuck lashed out at Adams.
"I laugh at stuff like that," he said. "It just just proves what kind of dirtbag he is."
When asked what happened at the end of the first half, Tuck said, "[The officials] blew the ball dead and I was headed toward the sidelines and pretty much had stopped. And somebody shoved me to the ground from the back and before I could get up he was [engulfed by] our sideline. So I didn't get to sneak any cheap shots in."
In the Cowboys' locker room after the Giants beat Dallas 31-24, Adams had this comment about Tuck: "I ain't talking about him. He's a nobody."
Adams was fined $7,500 by the NFL after kicking at Carolina defensive end Julius Peppers in Week 3. He was docked $5,000 for an unnecessary roughness penalty in the opener at Tampa Bay before the first incidents with the Giants.
Avoiding a suspension was crucial for the Cowboys, who are already playing without starting right tackle Marc Colombo. He has been out the last three games after breaking his left leg.
Information from Calvin Watkins of ESPNDallas.com, ESPN NFL Insider Adam Schefter and The Associated Press was included in this story.