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)