faint

"Faint" is an Old French word, and in both English and French it meant “faked, pretended, lazy, shirking, or cowardly” (a related French word gave us "feign"). Of the original meanings, only “cowardly” survives today in the phrase "faint of heart." The connotation of “weakness” was always there, however, and eventually "faint" came to mean “dim” (a “faint” light) and “weak and dizzy” (she looks “faint”). It became a verb in the 14th century, and then people were able to actually faint instead of just looking faint.