The deep-sea creature had slender, squid-like arms that swayed gracefully in the water.

squid-like 是由名词 squid（鱿鱼）加上后缀 -like（像...的）组成的形容词，意思是"像鱿鱼的"或"鱿鱼状的"。这个复合词用来描述某物在外形或特征上与鱿鱼相似。