Drinkable means safe or pleasant enough to swallow. Drinkable water, barely drinkable, a drinkable wine.
Of water it means safe, which is the important sense and is called potable in official writing. Of wine it is faint praise, since calling something drinkable says it is not good and will do.
1adjectivedrinkableSafe or pleasant enough to swallow.
“After the flood, the tap water was no longer drinkable, so we bought bottled water.”
drinkable is a quality.
Drink plus -able, in Middle English, from Old English drincan.
Middle English
drinkable
English, today
drinkable
From Middle English drinkable, drynkeable, equivalent to drink + able.
Etymology from Wiktionary, CC BY-SA