1670s, from ascribe + -able. Related: Ascribably; ascribability.
mid-14c., ascrive, from Old French ascrivre "to inscribe; attribute, impute," from Latin ascribere "to write in, to add to in a writing," from ad- "to" (see ad-) + scribere "to write" (see script (n.)). Spelling restored by 16c. Related: Ascribed; ascribing.