Cake Walk Meaning

(idiomatic) Something extremely easy.

Example: A type of dance originating in the United States in the 19th century.
1881, A.L. Bassett, “Our monthly gossip”, Lippincott's magazine, volume 28, page 208:
  It is called the cake-walk. A large cake is prepared for the occasion, and, when the invited guests arrive on the gala evening, each young man selects a partner for the walk. After a great deal of merriment and confusion, the couples take their places on the floor and begin to march around the room singing a hymn (for the church-members are not allowed to indulge in secular music) to a good marching tune, while the matrons and married men look on and criticise the promenaders, join in the chorus, and beat time with hands and feet. When tired at last of the walking-match, the cake is duly awarded to the most graceful couple, by whom it is carried home after the supper which closes the entertainment.
From the mid 1900s, a game at a fair or party in which people walk around a numbered circle along to music. When the music is stopped, the caller draws a number from a jar and whoever is standing on or closest to that number that number wins a cake.
1945, Robert L. Kilzer, “Cake-Walk Earns Money for Student Activities”, Educational Reading Service: School activities, volume 18, page 340:
  ... each of the marchers took his place beside the number nearest to him.
1922, New York Athletic Club, “Easy for Romig”, The Winged foot, volume 33, page 38:
  The three mile run was a cake walk for "Blondy" Romig, of Penn State.