What is the meaning of з-?

attached to imperfective verbs to form the perfective aspect

together (indicates bringing together literally or abstractly)

down (indicates downward movement)

off, off from (indicates removal or extraction from somewhere)

up (indicates upward movement)

indicates suddenness or abruptness

attached to imperfective verbs to form the perfective aspect

out (indicates intensity, extensiveness or exhaustion)

ex-, out (indicates elimination)

ex-, out (indicates outward movement)

Source: wiktionary.org

See also