Surname Cruc (Crux 
, Cruc 
) , all over the world, is quite a rare last name. The last name Cruc is habitual in Isle of Man, where it is quite a rare surname, Moldova, and El Salvador. Measured by absolute frequency, it is the most numerous in the United States, the United Kingdom, and El Salvador. Much less frequently, Cruc is the forename as well as the last name.