Meaning of “falter” - Learner’s Dictionary

falter

verb [ I ] uk us /ˈfɔːltər/
STOP BEING SUCCESSFUL

to stop being confident, powerful, or successful:

In the late 1980s his career began to falter.
MAKE MISTAKES

to pause, make mistakes, or seem weak when you are talking or moving:

Her voice didn't falter once during the ceremony.
a few faltering steps

(Definition of “falter” from the Cambridge Learner’s Dictionary © Cambridge University Press)