meaningful (adj)
Sens 1 : having a meaning or purpose: capable of being understood or interpreted:
requiring or done with understanding and intent. [source : MWU]
--------------------------------------------------
Sens 2 : constructed according to the rules of a language or system of signs:
having an assigned function in a system. [source : MWU]
--------------------------------------------------
Sens 3 : serious, useful, or important. [source : MAC]