writable adj read-write head n (Computing) an electromagnet that can both read and write information on a magnetic medium such as magnetic tape or disk write down vb adv 1 tr to set down in writing 2 tr to harm or belittle by writing about (a person) in derogatory terms 3 intr; foll by: to or for to write in a simplified way (to a supposedly less cultured readership) 4 tr (Accounting) to decrease