Declare as true is a phrase used to describe the act of making a statement that is accepted as fact. The crossword solutions for this term are AVER (4 letters), ASSERT (6 letters), and SWEAR (5 letters). AVER is a verb meaning to state or ASSERT as a fact, often with confidence. ASSERT is a verb meaning to state a fact or belief confidently and forcefully. Finally, SWEAR is a verb meaning to make a solemn promise or statement.