1.
Customary is used to describe things that people usually do in a particular society or in particular circumstances. (FORMAL)
It is ~ to offer a drink or a snack to guests...
= usual
ADJ: oft it v-link ADJ to-inf
2.
Customary is used to describe something that a particular person usually does or has.
Yvonne took her ~ seat behind her desk.
= usual
ADJ: ADJ n