An NX-class shower with no gravity
Soji Asha in a shower on Nepenthe
A shower is an area where one bathes under a spray of water.
In 2022, James T. Kirk took a hydro shower and commented how good it felt compared to the sonic variety "Well, that really beats a Sonic Shower" during a mission with La'an to 21st century Earth, when she and Kirk traveled back in time to stop an attack on Humanity's future. (SNW: "Tomorrow and Tomorrow and Tomorrow")
Showers were present on Earth Starfleet vessels during the mid-22nd century. Aboard NX-class starships of that era, a shower stall was a feature of an ensuite bathroom in the captain's quarters. The shower could be operated from a control panel outside the stall. (ENT: "Unexpected", "Singularity")
In 2151, Captain Jonathan Archer was showering in his quarters on Enterprise NX-01 when the artificial gravity went offline, sending him and the water droplets "floating" in the air. (ENT: "Unexpected")
The next year, Sub-Commander T'Pol attempted to clear Captain Archer of a specific kind of mind-altering radiation, which was being emitted from a nearby trinary star system, by washing him under a shower while he was fully clothed in his uniform. She activated the shower from the control panel outside the shower stall and watched from that position. Though Archer immediately asked her to turn the shower off, she waited until it became clear that Archer had regained his mental faculties, then deactivated the shower. (ENT: "Singularity")
In the final draft script of "Singularity", this shower was said to be on a cold setting while washing Archer fully clothed. [1]
While forced to hide at the catwalk in September 2152, Malcolm Reed asked Trip Tucker to build a shower and a sauna. (ENT: "The Catwalk")
In early January 2154, Doctor Phlox hallucinated that the shower in Ensign Hoshi Sato's quarters on Enterprise was being used by her while she was apparently fully clothed and had horrific facial effects of exposure to a trans-dimensional disturbance that, in both Phlox's hallucination and reality, was outside the ship. In Phlox's hallucination, the shower was on a hot setting, as evidenced by it meanwhile producing thick steam. In actuality, however, the shower wasn't even turned on and Sato was lying sedated on her bunk, where she was meant to be. (ENT: "Doctor's Orders")
Later that year, T'Pol had a nightmare in which she imagined herself taking a shower with Charles Tucker III and them kissing with increasing passion, T'Pol at one point pushing Tucker against the shower stall. As the nightmare continued, the imaginary T'Pol eventually became enraged and her face changed to show the horrific effects of trellium-D affliction, moments before the real T'Pol awoke. (ENT: "Damage")
In 2266, a man was found frozen to death in the shower with all his clothes on. (TOS: "The Naked Time")
By the 2270s, Starfleet vessels had begun to replace traditional, water-based showers with sonic showers. This was the case right up until at least the late-24th century. (Star Trek: The Motion Picture; TNG: "The Naked Now"; DS9: "If Wishes Were Horses"; VOY: "Juggernaut", "Pathfinder", "Live Fast and Prosper")
In 2370, Ensign Melora Pazlar explained to Doctor Julian Bashir that experiencing low gravity was "like slipping into a hot tub at the end of the day," to which Bashir joked, "I'm a shower man myself." (DS9: "Melora")
In 2399, Soji Asha took a shower while she was with Jean-Luc Picard at the Troi-Riker house on Nepenthe. (PIC: "Nepenthe")