The Chinese word for sponge is
海绵

hǎi mián

Chinese Definition

sponge
1. 名词. 海绵
2. 名词. 海绵动物
Components
海
1. sea; ocean
好想去看海。 - I really want to go and look at the sea.
2. big lake
洱海 - Er Lake
3. (Cantonese) wide river
4. (of containers, amount, etc.) big; large
海碗 - extra large bowl
海量 - huge amount
海投 - to send résumés to many companies; to use shotgun approach in job hunting
海扁 - to beat someone tremendously
5. overseas; abroad
海棗 - date palm
6. (figurative) sea; abundance; infiniteness
人海 - huge crowd
火海 - sea of flames
7. (dialectal, colloquial) profuse; numerous
8. (dialectal, colloquial) unrestrainedly; randomly; casually
9. . Hai (mainland China, Taiwan), Hoi (Hong Kong)
海瑞 - Hai Rui (Chinese scholar-official of the Ming dynasty)
绵
1. Simplified form of 綿