Grit

n.resilient, capableeveryday

Meaning 1

Practical courage and persistence sustained through difficulty.

Reach for it when praising continued effort when progress is hard and setbacks are real

It took grit to finish the qualification while working night shifts.

playful
backbone
informal praise should highlight moral courage
not when The idiom can sound accusatory when used to compare people.
professional
determination
a firm decision to reach the goal is central
not when Determination can be intense but brief; grit proves itself over difficulty.
professional
resilience
recovering and adapting after setbacks is the strength
not when Resilience emphasizes recovery, while grit emphasizes continued effort.
formal
tenacity
someone keeps hold of a goal despite repeated resistance
not when Tenacity can become obstinacy when the goal should be reconsidered.

Small hard particles of stone or sand.

Reach for it when using the literal material sense

A strip of grit on the icy step gave boots enough traction.

everyday
gravel
larger loose stone particles are meant
not when Gravel is usually coarser than grit and may not provide the same finish.
everyday
sand
fine natural grains are the material
not when Sand can be much finer and cleaner than road grit.
professional
abrasive
particles are chosen for their cutting or polishing action
not when An abrasive may be synthetic and need not resemble grit.
professional
aggregate
construction material of graded particles is intended
not when Aggregate is a technical category, not a direct substitute in household language.

show grit
The smallest team showed grit through every extra round.
true grit
True grit appeared when she returned to practice after the failed trial.
road grit
Road grit kept the steep crossing usable after the freeze.

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