Adhoc (adjective / adverb) — مخصّص / ارتجالي: Created or done for a particular purpose as needed, without earlier planning; a written form of 'ad hoc'. Below are 7 words with a similar meaning; the linked ones have full GL Dictionary entries with their meaning in Arabic.
Temporary and of poor quality, used because nothing better is available.
Done without preparation.
Arranged for now, possibly to be changed later.
improvisedunplannedspecial-purposecase-by-case