чмокнуть, чмокать - (легко поцеловать (обычно в щёчку)
Дмитрий, пожалуйста, допиши, что чмокать means also to make a loud short kissing sound by lips (not only when you kiss somebody) - it is always used by people who drive/ride the horse, also often by people which call the dog.

чмокнуть or as a weaker/shorter sound причмокнуть - means various sounds which have different meanings.
Such sound happens when you stretch your cheek back (when you wish to suck out from your tooth a disturbing piece of food) - as far as I know it has at least two meanings - the dissappointment and the expression of smelling or looking at something very tastefull/attractive.
ALSO!
The other sound which happens when you (with relaxed open lips) stick your tongue to the back of closed teeth and then fastly move the tongue back. The sound is similar with nts tsz or such.
Again, as I know, it can show such emotions like: dissappointment or (continuing fastly many times in a row) the thought that someone overestimates his abilities.

I am sure this particular and important additions will take a lot of attantion of your readers.
Please add them as soon as you can.