water strider vs pond-skater

water strider and pond-skater both are nouns.

Word	Noun	Adjective	Verb	Adverb
water strider	Yes	No	No	No
pond-skater	Yes	No	No	No

As nouns, water strider and pond-skater are synonyms defined as:

water strider and pond-skater: long-legged bug that skims about on the surface of water

Other synonyms of water strider include water skater.

water strider (noun)	pond-skater (noun)
long-legged bug that skims about on the surface of water	long-legged bug that skims about on the surface of water