Musk has suggested SpaceX will increase the number of engines on Starship from six to nine, as well as increasing the length of Starship to hold the requisite additional propellant. Such a vehicle would have considerably more thrust.

Recently Musk tweeted a picture of four existing Starships, calling them "the last of V1", with speculation being that "V2" might be such a nine-engine variant.

Will a nine-engine Starship variant launch in 2024?

"Launch" means lift-off from the pad, however slightly, either under the thrust of its own engines, or carried by a first-stage booster. Thus, launches of all kinds count: hops, suborbital, orbital, as long as Starship gets off the ground using rocket engines (its own or the booster's). Launches do not have to be successful, they just have to be launches.

The relevant timezone for "in 2024" is local time at the launch site (most likely: Boca Chica, Texas)