Able to be paid for or covered in cost by someone or some group.
From defray + -able suffix (capable of being). The -able suffix became productive in English during the Middle English period, turning verbs into adjectives describing possibility or suitability.
Defrayable is a specialized legal and business term that rarely appears outside formal contracts, which is why you probably haven't heard it before—it's essentially business jargon for 'payable.'
Complete word intelligence in one call. Free tier — 50 lookups/day.