One (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">one</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for unit that I've seen before include "A considerable number of soldiers" , "One; military group" , "Single manufactured item; military grouping" , "Individual thing or group regarded as complete" , "Module" .)
(Other definitions for sec that I've seen before include "Dry wine perhaps" , "Moderately dry, champagne say" , "sparkling?" , "(Of wines) dry" , "period not lasting long" .)