Earnings Before Interest, Taxes, Depreciation, and Amortization — the primary proxy for pre-tax operating cash flow before capital reinvestment, and the dominant metric for leverage sizing, valuation multiples, and covenant calculations in PE: EBITDA = EBIT + D&A. In credit agreements, 'Adjusted EBITDA' is contractually defined and typically includes add-backs for pro-forma cost savings from M&A (capped at 25% and 12-18 months run-rate), stock-based comp, restructuring charges, and other non-recurring items. The EBITDA-to-FCF bridge subtracts cash interest, cash taxes, capex, and ΔNWC.