Webster's Revised Unabridged Dictionary · 1913

Tacit

Tacit , adjective

[Latin tacitus, past participle of tacere to be silent, to pass over in silence; akin to Gothic þahan to be silent, Icelandic þegja, Old High German dagēn: compare French tacite. Compare Reticent.]

Done or made in silence; implied, but not expressed; silent; as, tacit consent is consent by silence, or by not interposing an objection.
The tacit and secret theft of abusing our brother in civil contracts. — Jer. Taylor