Pivotal
来自Big Physics
late Middle English: from French, probably from the root of dialect pue ‘tooth of a comb’ and Spanish pu(y)a ‘point’. The verb dates from the mid 19th century.
wiktionary
pivot + -al
etymonline
pivotal (adj.)
"of the nature of a pivot," 1844, in the figurative sense, from pivot (n.) in the sense of "that upon which something turns or depends" + -al (1).
