Buttress

v.resilient, capableprofessional

Meaning 1

To provide structural or practical support that prevents weakness or failure.

Reach for it when describing support added to a structure, system, or person

New cross-bracing will buttress the old timber frame.

playful
shore up
urgent practical support prevents further decline
not when Shore up is informal and often signals only a temporary repair.
everyday
support
general help or load-bearing assistance is enough
not when Support is broad and may be temporary or emotional.
professional
reinforce
added material or capacity strengthens a weak point
not when Reinforce may increase strength without propping against collapse.

To add evidence or reasoning that makes a claim stronger.

Reach for it when describing support for an argument

The survey results buttress the case for later clinic hours.

professional
bolster
added evidence increases confidence in the case
not when Bolster can improve appearance or morale without resolving a logical gap.
professional
strengthen
the argument becomes more persuasive or robust
not when Strengthen does not identify whether evidence, logic, or rhetoric changed.
formal
corroborate
independent evidence confirms part of an account
not when Corroborate requires another source and does not fit pure reasoning.
formal
substantiate
evidence establishes that a claim has factual support
not when Substantiate is stronger and may suggest the claim is proved.

buttress the argument
Two independent measurements buttress the argument for replacement.
buttress a wall
Timber frames buttress a wall until the mortar cures.
buttress the case
Patient travel data buttress the case for a mobile clinic.

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