ken (v.) Look up ken at Dictionary.com
"to know," Scottish dialect, from Old English cennan "make known, declare, acknowledge" (in late Old English also "to know"), originally "make to know," causative of cunnan "to become acquainted with, to know" (see can (v.)). Cognate with German kennen, Danish kjende, Swedish känna. Related: Kenned; kenning.
ken (n.2) Look up ken at Dictionary.com
"house where thieves meet," 1560s, vagabonds' slang, probably a shortening of kennel.
ken (n.1) Look up ken at Dictionary.com
"range of sight," 1580s, a nautical abbreviation of kenning.