faltering
Concise Oxford English Dictionary © 2008 Oxford University Press:
falter /ˈfɔːltə, ˈfɒl-/
▶verb lose strength or momentum.
■ move or speak hesitantly.
– derivatives
falterer noun,
faltering adjective,
falteringly adverb.
falterer noun,
faltering adjective,
falteringly adverb.
– origin ME: perh. from fold1 (which was occasionally used of the faltering of the legs or tongue) + -ter as in totter.
'faltering' also found in these Oxford entries:

