出乎 is a verb meaning 'to be beyond' or 'to exceed', but it is almost always used in the pattern 出乎 + noun-phrase (often 意料 'expectation') to mean 'beyond (one's) expectations'. It is a formal, slightly literary verb that does not appear in casual speech as a standalone; you will most often hear it in the fixed phrase 出乎意料 ('beyond expectations'). The 乎 is a classical particle, so the verb is treated as a single unit and is not separable.