to taste: to take a little food or drink into the mouth and tell what it is like, and so to learn something firsthand
Tasting in the Hebrew Bible is a small, deliberate act. A person puts a little of something in the mouth and finds out what it is like. That is why the word so often sits beside a word for a tiny amount: Jonathan lifts "a little honey" on the end of his staff, and the whole crisis of that chapter turns on one mouthful.
Because tasting is the smallest possible act of eating, it became the natural way to say that someone had eaten nothing whatever. Saul's curse on his army, David's oath while mourning Abner, and the king of Nineveh's fast all use it that way: not a bite, not a drop. English Bibles usually keep "taste" in these places, which reads well enough, though the point is going without food rather than sampling it.
From there the word reaches past the mouth. Job twice pairs it with the ear: the tongue sorts good food from bad the way a listener sorts good words from bad, and the comparison only works because tasting is already understood as a kind of judging. Two passages take the last step and drop the food altogether. "Taste and see that the LORD is good" invites a person to find out by going close, not by being told about it, and the capable woman of Proverbs 31 "tastes" that her trade is profitable, meaning she has handled it herself and knows.
The verb has a close relative, the noun טַעַם, which covers both a flavor and a settled judgment or official ruling. Jonah 3:7 sets the two side by side in a single sentence: the fast goes out by the king's decree, and what it forbids is tasting anything at all.