Respectful
Meek, respectful, self-effacing, unpresuming, unassuming, free from vanity, sycophantic, mim, deferential, submissive, unassertive, modest, self-deprecating, obsequious, servile, and resistless.
Lowly
Low-ranking, lowly, plebeian, working-class, poor, ignoble, low-born, common, ordinary, inferior, unremarkable, inconsequential, baseborn, low, lower-class, proletarian, undistinguished, mean, of low birth, of low rank, commonplace, simple, unimportant, insignificant, and plebby.
Simple
Lower
Humiliate, demean, lower, debase, bring low, shame, abash, chasten, take down a peg or two, cut down to size, make someone eat crow, abase, belittle, degrade, bring down, mortify, put to shame, subdue, make someone eat humble pie, put down, and settle someone's hash.