washing vs lavation

washing and lavation both are nouns.

Word	Noun	Adjective	Verb	Adverb
washing	Yes	No	No	No
lavation	Yes	No	No	No

As nouns, washing and lavation are synonyms defined as:

washing and lavation: the work of cleansing (usually with soap and water)

Other synonyms of washing include wash.

washing (noun)	lavation (noun)
the work of cleansing (usually with soap and water)	the work of cleansing (usually with soap and water)
garments or white goods that can be cleaned by laundering