1.(코/눈/입) 닦다 or 씻다 닦다 and 씻다 both mean "wash" or "wipe". So it means "wash/wipe one's nose", etc. But we don't use these expressions that much, except perhaps to tell children to do it. For adults, 세수하다 (wash one's face) is the most common term, but it is also declining in use because nowadays people take a shower more often(목욕하다, 샤워하다). 2. 보조를 맞추다, 발을 맞추다 보조 means the pace of walking, so 보조를 맞추다 and 발을 맞추다 mean the same thing. It can mean literally synchronizing the steps as in some military drills, but is more commonly a figurative way of saying "keep pace with" or "act or work closely together with someone". 3. 냉동어 and 냉동 생선 have the same meaning. 냉돋 생선 is more common in usage. 4. 차가운 물 is cold water. We don't use 냉동물 for "cold water" or "frozen water", if that's what you meant. Water freezes to become 얼음, and "ice water" (cold water with ice cubes in it) is 얼음 물 (or 아이스 워터). 냉동물 can sometimes mean frozen food or other stuff, where 물(物) doesn't mean water but things or stuff. 5. 말라서 뼈만 앙상하다 = be so skinny the bones are obvious (looks like a skeleton). 앙상하다 is an adjective for being thin and feeble without flesh, said of a body, tree branches, etc. 빼빼 (and the less popular 삐삐) is a (mimetic) adverb describing the way a body looks skinny. 빼빼 마르다 is a common expression for being too skinny.