A distinct slice of a structured debt facility with its own priority, pricing, amortization, and tenor. Common tranches: Revolver (committed undrawn, 25–50 bps commitment fee), Term Loan A (bank-held, amortizing), Term Loan B (institutional, bullet), DDTL (delayed-draw, ticking fee), Second Lien (junior to first lien on same collateral). In CLOs, tranches are rated AAA-down-to-BB with the unrated equity tranche absorbing first losses.