The term "lump sum" refers to a large amount of money. In financial terms, it involves investing a substantial amount of money in one go, rather than breaking it down into multiple installments.

A lump sum investment involves investing the entire available amount at once. For example, if someone wants to invest all their available funds in mutual funds or similar instruments, this would be considered a lump sum investment.

Similarly, a lump sum payment refers to paying the entire amount at once without breaking it into installments.