Pesach is
Hebrew for "pass over." The name commemorates the night of the
tenth plague,
the slaying of the firstborn. God told the
Children of Israel (through
Moses) that if they sacrificed a lamb and painted its blood on the doorposts of their homes, the
angel of death would
pass over their houses and spare their children. Practically speaking, this was probably also a good time for a sacrifice / feast, because they were about to
flee Egypt and wouldn't be able to take their livestock with them. In the modern
seder, the sacrifice is commemorated by the roast
shankbone on the table. The word
Pesach may also be extended to refer to the sacrificial lamb itself.
The adjective form of "Pesach" is
paschal. Which in English can refer to either Passover or
Easter. The
French name and word
pascal also means Easter.
On the equation of Passover with Easter, note that the Christian holiday of Easter occurs around the same time of year, that its story is set during Passover, and that it commemorates a similar sacrifice. In the
New Testament, John derides the Passover sacrifice as having merely saved lives, whereas the sacrifice of Christ saved
immortal souls.
Thanks to
Maayan for pointing out an inaccuracy in the original version of this post.