[1] : The Collaborative International Dictionary of English v.0.48

tacit \tac"it\, a. l. tacitus, p. p. of tacere to be silent, to
   pass over in silence; akin to goth. thornahan to be silent,
   icel. thornegja, ohg. dag=en: cf. f. tacite. cf.
   reticent.
   done or made in silence; implied, but not expressed; silent;
   as, tacit consent is consent by silence, or by not
   interposing an objection. -- tac"itly, adv.
   1913 webster

         the tacit and secret theft of abusing our brother in
         civil contracts.                         --jer. taylor.
   1913 webster
see also:
reticent tac"itly 

[2] : WordNet (r) 2.0

tacit
     adj : indicated by necessary connotation though not expressed
           directly; "gave silent consent"; "a tacit agreement";
           "the understood provisos of a custody agreement" syn:
           implied, silent, understood
see also:
implied silent understood 

[3] : Moby Thesaurus II by Grady Ward, 1.0

18 moby thesaurus words for "tacit":
   assumed, implicit, implied, inarticulate, inferred, intimated,
   silent, suggested, taken for granted, undeclared, understood,
   unexpressed, unsaid, unspoken, unstated, unuttered, unvoiced,
   wordless

[4] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

tacit. that which, although not expressed, is understood from the nature of 
the thing, or from the provision of the law; implied. 

Tacit >> T Words
Tacit, definition of term: Tacit
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