tedious (adjective) – long, slow and boring

tediously (adverb) – in a way that is long, slow and boring

tediousness/tedium (noun) – being long, slow and boring

 Tim Rodenberg

Examples:

I liked the book, but the movie, lasting three and a half hours, was rather tedious.

The young student wrote a tedious story about her trip, with lots of unnecessary details.

Make sure Uncle Bart isn’t going to do a speech. It will be too tedious.

George R.R. Martin’s novels are all extremely long, yet they don’t get tedious.

The meeting’s been tediously delayed again.

The article presented a tediously dry list of facts.

He isn’t so happy in his job anymore, due to the tediousness of a lot of routine tasks he needs to attend to every morning.

The children played games in the back of the car to break the tedium of the long ride.