Familiarity (5)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">familiarity</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for acquaintance that I've seen before include "contact" , "Person known, but not a close friend" , "Familiarity" , "Person known slightly" , "Slight knowledge" .)
(Other definitions for habit that I've seen before include "It's worn in order" , "Propensity" , "Routine - clothing" , "Ingrained behaviour" , "addictive practice" .)