inkpad vs inking pad

inkpad and inking pad both are nouns.

Word	Noun	Adjective	Verb	Adverb
inkpad	Yes	No	No	No
inking pad	Yes	No	No	No

As nouns, inkpad and inking pad are synonyms defined as:

inkpad and inking pad: a block of absorbent material saturated with ink; used to transfer ink evenly to a rubber stamp

Other synonyms of inkpad include pad, stamp pad.

inkpad (noun)	inking pad (noun)
a block of absorbent material saturated with ink; used to transfer ink evenly to a rubber stamp	a block of absorbent material saturated with ink; used to transfer ink evenly to a rubber stamp