AB - The interaction is significant!!
What this means is that if you now look at the effects of A for a level of B and compare it to the effects of A for another level of B, they may differ.

In English, the effect of year on Drinking would be different for each Gender. Maybe Males increase their drink more over the 3 years than Females. Maybe Males decrease drinking and females increase.

In any case, there can be differences between the years but these differences vary by gender.