Current portion of long-term debt definition including break down of areas in the definition. Analyzing the definition of key term often provides more insight about concepts. Current portion of long-term debt can be defined as: Portion of long-term debt due within one year or the operation cycle, whichever is longer; reported under current liabilities. It is common for long term debt to have a current portion and a long term portion. The current portion represents the principle only, not interest, that will be paid in a year.