The verb 'to apprise' is one of those verbs ending in the sound 'EYES' (IPA: /aɪz/) for which, despite the advice in -ise - -ize, the spelling with -ise "is compulsory" (Burchfield's Fowler). 'To apprise' also appears in Hart's list of 30 common verbs which are properly spelled with -ise. So, notwithstanding OED's recording apprize as a variant spelling, you are advised only to use the spelling apprise. (Notice that it has two '-p-'s.)
- The verb means basically 'to make [someone] aware' of something, 'to inform' of. It is quite common in the passive, for example "The general was apprised of the night's developments at 6:30 the next morning.".