The phrase "to marry a millionaire" means to become romantically involved with and eventually marry someone who is very rich and has a lot of money. Full definition
If, you have a clear goal and spent your efforts in dating a millionaire man, you will definitely marry a millionaire man early or late. (wantmillionaire.com)
But compared with the lasting happiness after marrying a millionaire, the effort and patience in finding a millionaire match is absolutely worth. (wantmillionaire.com)