What is "k-p-r"

K-P-R is a Semitic root, in Arabic and Hebrew rendered as K-F-R (in Arabic script: ; in Hebrew script: ). The basic meaning of the root is "to cover", but it is used in the sense "to conceal" and hence "to deny", and its notability derives from its use for religious heresy or apostasy (as it were describing the "concealment" of religious truth) in both Islam and Judaism.