prevalent
PREV-uh-luntadjMeaning widespread; common in a place or at a time
Memory hook PREV-ALL-ent: nearly ALL have one. When it rains in our town, nearly all of us carry red umbrellas. Red umbrellas are prevalent here.
Colds are most prevalent in the winter months.
In context Hats were once prevalent, so common that hardly anyone left home without one, but by the 1970s most people went out bareheaded.
Similar widespread, common, rife, prevailing
Opposite rare, uncommon, scarce
From Latin praevalere, “to be stronger, to win out”: prae (before, above) + valere (to be strong).