is it when they're five sheets to the wind, or when their eyes are blurry or unfocused, and their speech is slurred, or when they're like that, are they only ''showing their liquor'' or " feeling their liquor " ? and my dad, after 4 or 5 drinks, he'd get argumentive and his eyes didn't look like himself. Is that drunk ? 

 I don't know. Is it subjective or is their some criteria or cut off line when you say a person is drunk?. Is it only when they're falling down drunk or violent, or what ? I've heard people that they're drunk. What do they and you  consider drunk......when they have trouble walking or thinking ? or when they slur their speech ? My  girl  friend was definitely under the influence the other night when I was trying to hang out with her. And she was getting maudlin saying she loves me " better than sh*t " and I'm her "BFF ''  and she told my sig other that she loved him too. Ha ha. 

   Most of the time she's sober, but she said she drank the other day b/ c she didn't have anything to do and nobody to talk to until the evening.

Addendum :  her speech was slurred, and her eyes looked unfocused.