loan shark 
noun informal, derogatory
A moneylender who charges extremely high rates of interest, typically under illegal conditions: reports of exploitation and deceptive trading practices by loan sharks...
- Others make frequent trips to pawn off paychecks at an interest rate a loan shark salivates over.
- The rates may not seem onerous to borrowers when their only other source of credit is a loan shark.
- Credit card holders know that borrowing on their card without repaying in full at the end of each month is the most expensive form of borrowing available - short of approaching a loan shark.
- roundheel
- roundheeled
- round-heeler
- round herring
- round-hoofed
- roundhouse
- roundhouse kick
- rounding error
- rounding-off error
- rounding up
- roundish
- roundishness
- round-leafed
- round-leaved
- round-leaved sundew
- roundlet
- round log
- round lot
- roundly
- roundman
- round meal
- round-mouth
- round-mouthed
- round-neck
- round-necked