Trayce Jackson-Davis paced the Hoosiers' comeback with 17 second-half points.
Morsell is out after suffering a facial fracture against No. 16 Michigan on New Year's Eve.
Diamond Miller finished with a team-high 15 points.
Smith scored a career-high 29 points to fend off the Hoosiers' second-half rally.
The Terps are seeking their third straight win.
Guard Taylor Mikesell shot 6-for-7 from the field and contributed 16 points.
Smith finished with 19 points and eight rebounds over the course of 25 minutes.
Jalen Smith scored a game-high 19 points.