Answer: squishing

AnswerCrossword Clue
SQUISHINGMaking a walking-in-mud sound
squishingSQUISH, to squash (to press into a flat mess)
squishingSquash (something)
squishingMake a soft squelching sound when walked on or in
squishingSqueeze oneself into somewhere
squishingYield easily to pressure when squeezed or squashed