Visual: A short word, six letters, but with some vertical. It has an overall trend from upper left, with the f ascender, through the lower r and s mixed with the dotted i and high k, to lower right on the y descender. It has verticals, a cross-bar, curves, a hump, a dot, and diagonals: nary a thing missing in its quick frolic through typographical shapes.
In the mouth: It launches with the erupting embouchure of [fr], which may have voicelessness spreading from the [f] onto the [r] to make a sound like a rocket or the “sending” sound in Mac Mail. The lips then pull back in two stages: neutral for the first vowel, then pulling back wider at the end – after the tongue has hissed off the tip with [s] and kicked off the back with [k]. If it’s a rocket, it’s one that quickly launches through stages and goes off out of sight almost before you see it.
Etymology: Frisky (adjective) comes from frisk (noun), which comes from frisk (verb), which comes from frisk (adjective, obsolete), which comes from… um, there are two possible options. One is that it’s from the Germanic root that gives us fresh (and modern German frisch, which means the same thing). The other is that it’s from Middle French frique ‘lively, smart’, which in turn comes from Germanic. Either way it’s from Germanic and has danced around rather a lot, including looping a full circle from frisk adjective to frisky adjective like a dog chasing its tail.
Collocations: Often you feel frisky or are feeling frisky (never mind groovy), and may be particularly frisky; if you are frisky you are also likely young and may be a pup or a colt or even a goat (but not so likely, it seems, a kid).
Overtones: The word starts with the frothy fresh [fr], which shows up in a variety of words, including a fair few that are well served by saliva spraying forth from the mouth: fracas, frappé, fraught, fray, frazzle, freak, fresh, friction, frizzy, frolic, frosh, frothy, and frustration, not to mention frith. It then sharpens that feeling (like adjusting the nozzle on a hose from spray to jet) with the risky, which also smacks of whisky, whisk, brisk, and perhaps mist and disk and maybe even crispy. And if you look you can see the sky.
And then there’s that other common sense of frisk, first seen in the late 1700s: to manually search someone’s person by going through their clothes etc. while they’re still wearing them. I suppose if you were to do a similar patdown on your paramour he or she might find it rather frisky. Anyway, it’s directly derived from the verb frisk meaning ‘frolic, be frisky’, at least as far as anyone can see. And it may lurk in the background when this word skips across the lawn of your mind.
Semantics: Picture a puppy, especially a Labrador puppy. A little ball of energy. Incessantly wanting to play. Frolicsome. Wagging the tail with the whole body. Jumping up, licking, barking, running around. Frisky. Almost too much to handle. But happy!
Of course, anything or anyone particularly playful can be “frisky.” But among humans, it seems especially to connote a particularly sexual inclination: for puppy love substitute concupiscence – but you can retain much of the other described behaviour, if in some respects figuratively.