Definition of bum-sucking in English:

bum-sucking

noun

vulgar slang British
  • The use of flattery or other obsequious behavior in order to gain favor.

    obsequiousness, sycophancy, excessive deference, subservience, submissiveness, fawning, toadyism, toadying, grovelling, cringing, unctuousness, oiliness, abjectness, abjection, cravenness, slavishness, humility, self-abasement