Sentence:  Considering the results of the study, today John may be buoyed at the clear trend of increasing numbers of new “lishes” for each successive decade since the 1950s, and the fact that nothing in the data suggests this trend is likely to <WSD>falter</WSD>. 
Meaning of the word marked with <WSD> tags:  To waver or be unsteady; to weaken or trail off.