ponzi

As a noun terms

is .

As an adjective ponzi is

whereby investors' returns are paid for directly by later investors' investments, giving the false impression that the investment is viable.

As a noun pyramid

is an ancient massive construction with a square or rectangular base and four triangular sides meeting in an apex, such as those built as tombs in egypt or as bases for temples in mesoamerica.

As a verb pyramid

is (genetics) to combine (a series of genes) into a single genotype.

As an adjective ponzi is

whereby investors' returns are paid for directly by later investors' investments, giving the false impression that the investment is viable.