Noun: Ablution. (The act of washing oneself.)
(The sign in today’s example points out that one bath (kylpy) uses as much water as 5 showers (suihku) at 12 liters of water per minute.)
Peseytyminen is a nominalized (”nounalized”) verb (also known as the fourth infinitive) made by taking the root of the 3rd person plural of peseytyä, which means ”to wash up” or ”to wash,” removing the -vat ending and adding the suffix -minen. The 3rd person plural of peseytyä is peseytyvät, so the root is peseyty to which you simply add the suffix.
In English an example of this type of noun is ”running,” formed by adding -ing to the verb ”run.” This type of noun is called a gerund.
In Finnish, nominalized verbs ending in –minen are declined just like nouns ending in -nen such as nainen or suomalainen.
Other common nominalized verbs in Finnish are lukeminen (reading) or nukkuminen (sleeping.)