Mat 15:6 And he need not honor his father nor his mother. Thus have you made the commandment of God have no effect by your tradition.

This is a typical example of Christ setting the priority of the spiritual (commandments of God) over social convention. It is also an example of emotions and personal relationships (in this case with relatives) trumping less personal relationships and the realm of the words.

Alternative translation: And [people] need not honor their fathers and mothers and canceling a command of God by what you have passed down.

"Make to have no effect" is from akuroô, which means "to cancel," "to set aside," and "to treat as if it has no effect." It is a metaphor for "to render powerless."

"Tradition" is from paradosis , which means "handing down," "transmission," and "that which is handed down." This specifically includes legends, traditions, and doctrines but it is not specific about the quality of what is handed down, only that it has been passed down.