sing-kwa vs rag gourd

sing-kwa and rag gourd both are nouns.

Word	Noun	Adjective	Verb	Adverb
sing-kwa	Yes	No	No	No
rag gourd	Yes	No	No	No

As nouns, rag gourd is a hypernym of sing-kwa; that is, rag gourd is a word with a broader meaning than sing-kwa:

sing-kwa: loofah of Pakistan; widely cultivated throughout tropics
rag gourd: any of several tropical annual climbers having large yellow flowers and edible young fruits; grown commercially for the mature fruit's dried fibrous interior that is used as a sponge

Other hypernyms of sing-kwa include dishcloth gourd, luffa, sponge gourd, strainer vine.

sing-kwa (noun)	rag gourd (noun)
loofah of Pakistan; widely cultivated throughout tropics	any of several tropical annual climbers having large yellow flowers and edible young fruits; grown commercially for the mature fruit's dried fibrous interior that is used as a sponge