Answer : 신발끈(that means shoelace)
Explanation&Learning Korean
The term “신발끈” (shoelace) is a combination of “신발” (shoe) and “발끈” (a sound word representing getting angry or bristling). The humor comes from the idea that when a shoe gets angry, it “발끈” (bristles up), and this phrase combined with “신발” (shoe) creates “신발끈” (shoelace). It’s a pun that plays on the double meaning of “발끈,” both as part of the word for shoelace and as an expression of anger.