“The Radio City Christmas Spectacular” (8 p.m., NBC): More holiday cheer comes our way

“The Radio City Christmas Spectacular” (8 p.m., NBC): More holiday cheer comes our way with “The Radio City Christmas Spectacular.” It’s a one-hour production featuring glamorous costumes, dazzling special effects and performances by the Radio City Rockettes. Matt Lauer and Meredith Vieira are your hosts.

“iCarly” (8 p.m., Nickelodeon): Carly Shay (Miranda Cosgrove), the once-shy 13 year old who’s host of her own online show, must outwit a rival’s plans to hack into the iCarly Web site. Will she and her friends Sam and Freddie succeed? This episode features a guest spot by the band Plain White T’s, performing their latest single, “Our Time Now.”