sak-
“to sanctify, to make holy”sacred/sanctify
PIE root meaning to sanctify or make holy. Source of Latin sacer, English "sacred," "saint," and words for consecration.
Discussion
*sak- is a Proto-Indo-European root meaning "to sanctify" or "to make holy," one of the most productive roots in Indo-European religious vocabulary.
Latin sacer "sacred, holy" is the central reflex, yielding an enormous family: English sacred, sacrifice, sacrament, sacrosanct, sacrilege, saint (via sanctus), sanction, and sanctuary. The Latin development from sacer through sancīre "to make sacred" (with nasal infix) produced the participial sanctus "holy," source of saint and sanctify.
Oscan sakrim and Umbrian sacra confirm the Italic attestation. Hittite šākk- "to know" may be related, with a semantic shift from "sacred knowledge" to knowledge generally, though this connection is debated.
The root belongs to PIE sacral vocabulary alongside *ḱred-dʰeh₁- "to believe," *seh₂k- "to consecrate," and *ǵʰew-t- "to invoke." The distinction between *sak- and *seh₂k- remains debated—they may be ablaut variants of one root.
The productivity of this root in Latin has given English its richest cluster of religious terminology. Modern descendants include sacred, sacrifice, saint, sanction, sanctuary, sacrilege, sacrament, sacrosanct, and consecrate.
Notes
Source of Latin "sancīre" (to make sacred), "sanctus". Related to *seh₂k-.