Onomatopoeia:
* Lick - Simple and direct.
* Slop - Suggests a wet, messy lick.
* Slap - Can be used for a quick, forceful lick.
* Slurp - For a louder, more drawn-out lick, especially with liquids.
* Gulp - For a quick, forceful lick with a swallowing motion.
Other options:
* The sound of a tongue touching something - This is more descriptive than onomatopoeia.
* A soft, wet sound - This is more abstract but can convey the texture of a lick.
Ultimately, the best spelling for a licking sound depends on what you're trying to convey. Choose the option that best fits the context and the feeling you want to evoke.