definition from
Oxford Dictionary of English –

motto /ˈmɒtəʊ /
▸ noun
(plural mottoes or mottos)
1 a short sentence or phrase chosen as encapsulating the beliefs or ideals of an individual, family, or institution:
the family motto is ‘Faithful though Unfortunate’.
2 Music a phrase which recurs throughout a musical work and has some symbolical significance:
they were developing the use of leitmotifs or mottoes that appear throughout an opera.
– ORIGIN late 16th century : from Italian, ‘word’.