Merriam-Webster defines “crass” as follows:
1 a : GROSS 6a; especially : having or indicating such grossness of mind as precludes delicacy and discrimination b : being beneath one’s dignity
c — used as a pejorative intensifier
2 : guided by or indicative of base or materialistic values
For a real-world illustration of “crass”, see here.
(via Pajamas Media)