I always thought "fit & finish" are obvious.
Fit refers to how good the parts come together. A bad fit can mean too loose (gap, play, flex, rattle, etc.) or too tight (hard to operate, scratches from rubbing, etc.) Finish refers to completeness or perfection of the work. A poor finish can mean less than sharp cutting edge, visible surface imperfections, burrs, spots, rough edges, etc.
These two characteristics usually reflect the quality of the design and craftsmanship. A knife can utilize the best steel and materials in the world, but if it has poor fit and finish then it's badly made. A knife can also use non spectacular steel and materials yet feels well made (like a Victorinox).