Literally "watcher", usually a priest

The waki actor serves to support the main actor, and thus performs the roles of waki and waki-tsure. Depending upon the play, they might be Shinto priests, Buddhist monks, or samurai, but they are always roles portraying real, living men. The waki does not wear a mask.

Protagonist

The type of character portrayed depends upon the type of play being performed, but the majority of characters range from the spirits of men and women and even plants or trees, to gods, demons, and supernatural beings. In principle, there is a Noh mask appropriate for each main role.

The 3 moods that are structured as a part of the Noh Festivals. 

In following with the writings of Zeami, all major forms of Japanese traditional drama (Noh, kabuki, and jōruri) utilize the concept of jo-ha-kyū in the choice and arrangement of plays across a day, to the composition and pacing of acts within a play, down to the individual actions of the actors.

Walkway on/off the stage, a way to "pass between worlds" 

A bridge that connected the stage to the dressing room. It was located 33 to 52 feet (10 to 16 metres) to the audience’s left. This allowed for long dramatic entrances and exits.

1363-1443 

Most well know playwrigh/theorist of Noh theatre.

He and his father were the creators of the Noh drama in its present form. 

He is credited with about 90 of the approximately 230 plays in the present repertoire (Wrote Atsumori)

Said the actor must master 3 basic roles: the warrior, the woman, and the old person, including the singing and dancing appropriate to each.

The two main elements in Noh acting were monomane, “an imitation of things,” or the representational aspect, and yūgen, the symbolic aspect and spiritual core of the Noh, which took precedence and which became the touchstone of excellence. 

Comic interludes (plays) in between the dramas in day long festivals, used a lot of slapstick physical comedy

Also refers to the comic performers themselves