In modern English, sycophant denotes an "insincere flatterer" and is used to refer to someone practicing sycophancy (i.e. insincere flattery to gain advantage). The word has its origin in the legal system of Classical Athens. Most legal cases of the time were brought by private litigants as there was no police force and only a limited number of officially appointed public prosecutors. By the fifth century BCE this practice had given rise to abuse by "sycophants": litigants who brought unjustified prosecutions. The word retains the same meaning ("slanderer") in Modern Greek and French (where it also can mean "informer"). In modern English, the meaning of the word has shifted to its present usage.
We ‘go along to get along’ in defiance of what we really value or believe because we don’t want any trouble. Immanuel Kant calls this sort of excessively deferential attitude servility. Servility involves downgrading your own values and commitments relative to those of others. Instead of stepping on whomever is in his way to get what he wants, the servile person is, in Kant’s words, someone who ‘makes himself a worm’ and thus ‘cannot complain afterwards if people step on him’.