Turnkey

adj.capable, hopefulprofessional

What it means

Ready for the intended user to operate with little additional setup.

Reach for it when describing a substantially complete solution while stating what setup and support remain

The charity received a turnkey laundry unit with training, spare parts, and utility connections.

playful
plug-and-play
when simple connection and automatic operation fit technology
not when Plug-and-play is device-specific and frequently understates configuration.
everyday
ready-to-use
when immediate practical operation needs plain language
not when Ready-to-use may apply to one item without including an entire delivered system.
warm
move-in ready
when a property can be occupied immediately
not when Move-in ready is property-specific and may ignore utilities or accessibility.
professional
fully equipped
when all necessary tools or fittings are present
not when Equipment can be complete while installation and training remain unfinished.
professional
off-the-shelf
when a standard product can be purchased without custom development
not when Off-the-shelf can still require extensive integration.
formal
operational
when a system is functioning now
not when Operational describes current state and not how much setup the buyer must perform.

turnkey solution
The turnkey solution included migration, testing, and staff training.
turnkey system
A turnkey system gave the clinic a working backup from day one.
turnkey facility
The contractor delivered a turnkey facility after the final safety inspection.

Turnkey is often marketing shorthand; exclusions, dependencies, training, and ongoing support should be explicit.

The definition and the example on this page are written here. The dictionaries above ground which meaning is being described, not the wording.