washing vs washing-up

washing and washing-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
washing	Yes	No	No	No
washing-up	Yes	No	No	No

As nouns, washing-up is a hyponym of washing; that is, washing-up is a word with a more specific, narrower meaning than washing:

Other hyponyms of washing include bathing, washup, ablution, dishwashing, washup, window-washing, rinse, soak, soaking, laundering.

washing (noun)	washing-up (noun)
the work of cleansing (usually with soap and water)	the washing of dishes etc after a meal
garments or white goods that can be cleaned by laundering