MacOS – Single click and select whole word

Yep!

You double-tap and lift off to select the word. Then double-tap the selected word and start dragging immediately keeping your finger down. It's actually kind of tricky to get to work without dragging the word but once you get it a couple of times it gets easier.

Here's an explanation on how to do it also from macworld.com, same as above:

To select text (and this works in nearly any program that involves text) on a word-by-word basis, do a double-click-and-hold before you start dragging, instead of a single click. As you move the mouse along now, you’ll see that entire words are added to your selection as soon as the cursor touches their first character. So if you’ve got a fair bit of text to select, but still need precision, this is a pretty quick way to get it done.

Here are my trackpad settings

You might want to take a look at iTerm2, where you can set the word delimiter in the preferences. I'm a recent convert myself and like it a lot better than Terminal.app. There's a special Terminal.app keyboard shortcut compatibility set to make switching easier.