A-OK

adj.capable, hopefulplayful

What it means

Completely satisfactory, safe, or functioning as it should.

Reach for it when giving relaxed reassurance after a check or a period of concern

The engineer inspected the repaired lift and confirmed that it was A-OK.

playful
shipshape
tidiness and readiness deserve a jaunty tone
not when Shipshape focuses on orderly condition, not health or emotional well-being.
everyday
all right
simple reassurance is more important than enthusiasm
not when All right can mean merely adequate, while A-OK signals a clean bill of health.
everyday
fine
an informal answer needs to sound effortless
not when Fine is easily heard as reluctant when the reassurance must be unmistakable.
professional
in working order
equipment has been tested and functions correctly
not when The phrase applies to mechanisms, not a person's general well-being.
professional
satisfactory
a result has met an explicit standard
not when Satisfactory sounds measured and can understate genuine relief.
professional
sound
inspection has established structural or practical reliability
not when Sound is too technical for cheering up someone after a minor worry.