It's not just that stuff underneath your fingernails.
The word is on the back of shirts that Texans players, coaches and staff members have worn, and it's a term the team has embraced in 2016.
Bill O'Brien said the team picked it up from Dr. Kevin Elko, who's spoken to the Texans numerous times. He'll be back on Friday morning to talk with the squad ahead of their Wild Card playoff matchup with Oakland, and the head coach explained what 'grit' means.
"When something goes wrong, or not your way, don't look to blame somebody," O'Brien said. "Just look to line up and play the next play. Have the grit, the intestinal fortitude to put one foot in front of the other and deal with adversity."
Tough times strike every team. The successful ones, however, are able to overcome the adversity and thrive.
"You see all the shirts around here," linebacker Whitney Mercilus said. "The importance to having grit honestly is having a really tough football team, just understanding there's going to be tough situations, some adverse situations, some mistakes that happen out there. That grit is what carries you through to overcome all those adverse situations."
Mercilus is one of several Texans who have filled the void created by the loss of 3-time NFL Defensive Player of the Year J.J. Watt. The team also lost cornerback Kevin Johnson to injury, and on offense, the Texans have seen center Nick Martin, right tackle Derek Newton and several others head to injured reserve.
But despite those health setbacks, grit has helped steel the Texans' collective resolve.
"It's really important," receiver Will Fuller said. "I feel like that's how our team - we took that in. A lot of injuries on the team but we never made any excuses, so grit is a big part of our team."
O'Brien, though, emphasized that grit can help shine a bit of light on what can make a team successful too.
"If you're riding the wave of good things, hey, keep it going," O'Brien said. "Understand why you're doing that. Have the grit to understand why you're having success right now. I think that's big in the NFL."
The Texans will host the Raiders on Saturday inside NRG Stadium at 3:35 p.m. CT.
The Houston Texans roster in photos. (Updated 2/24/2021)