Noun

1. A list of names, usually for an organisation of some kind such as military officers and enlisted personnel enrolled in a particular unit; a muster roll; or a sports team, with the names of players who are eligible to be placed in the lineup for a particular game.
2. A list of the jobs to be done by members of an organisation and often with the date/time that they are expected to do them.

   The secretary has produced a new cleaning roster for the Church over the remainder of the year.

Verb

1. The act of placing a name on a roster.

   I have rostered you for cleaning duties on the first Monday of each month.