Life-changing

adj.hopeful, capablewarm

What it means

Producing a major and durable shift in how someone lives.

Reach for it when describing an opportunity, event, insight, or intervention with profound personal effects

Access to the hearing device was life-changing for the retired teacher.

playful
game-changing
informal emphasis on a major practical advantage suits
not when Game-changing sounds promotional and often concerns competition rather than a life.
professional
influential
the experience shaped later choices without wholly transforming them
not when Influential is more modest than a genuinely life-changing effect.
professional
profound
depth of effect is clear but its direction is not
not when Profound alone does not say that daily living changed.
professional
transformative
deep change in capacity, outlook, or systems is documented
not when Transformative can apply to organizations and need not alter a person's life.
formal
pivotal
one moment decisively redirects what follows
not when Pivotal marks importance but does not guarantee improvement or lasting change.
literary
momentous
the event carries great consequence and ceremony
not when Momentous can describe public history without changing one life.
literary
turning-point
the change divides a personal before and after
not when Turning-point is awkward as an adjective and can mark a negative shift.

life-changing opportunity
The residency offered a life-changing opportunity to study marine biology.
life-changing decision
Moving closer to treatment proved a life-changing decision.
potentially life-changing
The trial offers potentially life-changing relief, though results remain uncertain.

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