constant
adj.
late 14c., "steadfast, resolute," from Old French constant (14c.) or directly from Latin constantem (nominative constans) "standing firm, stable, steadfast, faithful," present participle of constare, from com- "together" (see com-) + stare "to stand," from PIE root *sta- "to stand" (see stet). Of actions and conditions from 1650s. Related: Constantly.
n.
1832 in mathematics and physics, from constant, adj..
〔李〕[con-(com-)=thoroughly彻底地；st=to stand站立；-ant a.=-ing……的→“standing thoroughly始终站立的”→] a.① fixed or firm坚定的