n.
 (pl. truths  
/truːðz, truːθs/
)
 the quality or state of being true. 
▸
(also the truth)
 that which is true as opposed to false.
 ▸a fact or belief that is accepted as true.
 
  Phrase
  
    - in truth
 really; in fact.  - to tell the truth 
(or truth to tell or if truth be told)
 to be frank. 
   
  Etymology
  OE trīewth, trēowth ‘faithfulness, constancy’ (see true, -th2).