kellastu
Kellastu is a Finnish verb that translates to "to turn yellow" or "to grow old" in English. It is often used in a figurative sense to describe things that are fading, deteriorating, or becoming aged. For example, one might say a leaf has "kellastunut" in autumn, referring to its change in color. The verb can also be used to describe a person's aging process, implying a sense of weariness or decline. In some contexts, "kellastu" can also refer to the yellowing of teeth or skin due to various factors like smoking or illness. The word's etymology is rooted in the Finnish word for yellow, "keltainen."