YA HYA CHOUHADA is a Fremen saying meaning "Long live the fighters!" The Fedaykin battle cry. Ya (now) in this cry is augmented by the hya form (the ever-extended now). Chouhada (fighters) carries this added meaning of fighters against injustice. There is a distinction in this word that specifies the fighters are not struggling for anything, but are consecrated against a specific thing -- that alone.
It is also the motto for the FED2k website.