1 tr. write on top of (other writing).
2 tr. Computing destroy (data) in (a file etc.) by entering new data.
3 intr. (esp. as overwritten adj.) write too elaborately or too ornately.
4 intr. & refl. write too much; exhaust oneself by writing.
5 tr. write too much about.
6 intr. (esp. as overwriting n.) in shipping insurance, accept more risk than the premium income limits allow.
Useful english dictionary. 2012.