hawaladar, n. Hawala is a system for making international payments in Arab and South Asian countries. ... Hawala is from the Arabic for “promissory note, letter of credit.”
You might add that the last syllable is from Persian dār ‘holder,’ which also shows up in sirdar and zamindar (as well as in a couple of even less common words); it’s from PIE *dher-, which also gives the dhar- of dharma and the Latin word firmus, with its many English derivatives.
