fad

Concise Oxford English Dictionary © 2008 Oxford University Press:
fad/fad/

▶noun

• 1 a craze.

• 2 an arbitrary like or dislike.

– derivatives
faddish adjective,
faddishly adverb,
faddishness noun,
faddism noun,
faddist noun.

– origin C19 (orig. dial.): prob. the second element of fidfad, contr. of fiddle-faddle.