clogged kitchen sink with sitting water?

get the plunger

Have you tried a bathroom plunger? What lead to this? Are other things in the house backed up too? If so you may have to have it roto rooted…

if the plunger don’t work get as much of the water out of the sink as you can and go under take the s bend off and see if its stoped up there if it is unstop it if it is not and the water is still in the sink then take the pipie down from the sink and find the clog there if the rest of the water came out of the sink when you took the s bend out the get a drain snake and run it in the pipe that goes under the house that should push the clog out

they sell a spray can that blasts the crap right out

Does your sink have two basins? If so plunging is a chore. You have to make sure one side, the one without the J pipe under it, is totally “sealed” or you are just moving water from one basin to the other.
If the sink water level remains constant and does not lower, you have a complete blockage someplace. If it does slowly lower, you have a partial blockage.
I would first try to remove the J pipe underneath the sink and see if that is what has accumulated grease, yuck or whatever. If it is clean, your problem is farther down the line.
Some houses have clean outs–a plug in the main drain that can be removed for access to the pipe, then reamed out going one way or the other–up to the plugged area or down to the plugged area.
In some cases, partial plugs down the line can be identified by listening for gurgling sounds from either your washing machine drain pipe or worse, if you get some drainage but not a lot, bubbling back through the toilet or shower system.
All that means bring in the pros. Even if you have a power snake, getting it to go through all the bends and elbows and traps along the way is really difficult, and it may not be long enough to reach the true blockage.
If everything else is draining fine, no noise or gurgling or back up, the problem is between your sink drain and the main it runs to. In that case, you could remove the J pipe and try a snake line, depending on the distance between the two. You run the line parellel to the floor through the pipe the J is connected to and that goes through the wall. Bring the line back occasionally to see if you have collected anything on the end, so you will know what is causing your problem–grease, hair, accumulated food particals, etc. Usual internal problem is grease buildup.