Help, guidance, or advice given to someone in a manner that does not offer or tolerate leniency in rules or discipline. Treating someone in such a way can be done in general or, as is often the case, to try to change behavior or a particular problem, such as addiction. That boy's parents let him do whatever he wants, but he's in for some tough love when he gets to his grandmother's house—she's kind but strict! What I really wanted when I went to rehab was tough love, instead of more people enabling me.