Description:

The base meaning of 'katen' is 'spouse'. The implication is a romantic partner formally and legally joined.

Noun:

As a noun, 'katen' refers to the person of a spouse. It is often derived with intrinsic gender prefixes  to be used as likáten and cekáten, wife and husband, respectively. The derived terms katenysyn for marriage in general or a specific marriage, and katencel for a wedding.

Affix Forms:

There are some commonly used forms of katen as an affix:

As 'katen-' it is used in words for familty relations to specify that a person has a certain relationship status by marriage. So for example 'katennoakki' means 'fictive aunt or uncle through marriage to real elder aunt or uncle'. If a gender prefix is used it is applied to the head of the compound, and agrees with the gender of the person, not the person through whom the relationship is mediated.

As 'katenys-', it is used to derive words for relatons through one's own spouse. The difference between 'katen-' and 'katenys-' may not seem to flow naturally, but that's just the idiom in Common. Take any relationship word and prefix it with katenys- and is specifies that the relationship is through your significant other.

Verb:

Katen has some currency as a verb meaning to marry. As such it isn a ditransitive noxaj verb with an absolutive subject which is the partner in the marriage who is the topic and a dative indirect object, who is the person that that person is marrying.

It can be used dinintentively as an intransitive pali verb, in which case it can take a single absolutive subject which is a person getting married without focusing on the fact they are marrying someone specifically, or with two absolutive subjects joined with 'epis', which are marrying each other - in this form, the focus is not on one of the other. Either the disintentive or regular forms can be made causitive, in which case they add an ergative subject who is officiating the wedding.