On a piece of music, how should you play if it has 'mf' written by it?
Correct answer: Moderately loudly

Player #92723922
Also:
pp - very quiet
ppp -:very, very quiet
ff - very loud
fff - very, very loud
Often "quiet" is expressed as "soft"

Player #97184361
herb198220, That should not be a surprise if the trend is followed