| Acronym | Definition |
|---|
| MSSB➣Morgan Stanley Smith Barney LLC (finance) |
| MSSB➣Mechanical Services Switch Board (electrical power) |
| MSSB➣Modified Statutory Solvency Basis |
| MSSB➣M Shanghai String Band (Brooklyn, NY) |
| MSSB➣Metropolitan Separate School Board (Toronto Catholic district) |
| MSSB➣Maple Story Social Board (GameFAQs message board) |
| MSSB➣My Social Stories Book (teaching aid; book) |