a.  1.  One and one; twice one.
 
n.  1.  The sum of one and one; the number next greater than one, and next less than three; two units or objects.  
2.  A symbol representing two units, as 2, II., or ii.

Noun  1.  two  the cardinal number that is the sum of one and one or a numeral representing this number 
Adj.  1.  two  being one more than one; "he received two messages" 