Groveler and Yes-man

Groveler noun - Someone who humbles himself as a sign of respect; who behaves as if he had no self-respect.

Yes-man and groveler are semantically related In some cases you can use "Yes-man" instead a noun "Groveler".

Yes-man noun - A person of unquestioning obedience.

Groveler and yes-man are semantically related in someone following orders without question topic. Sometimes you can use "Groveler" instead a noun phrase "Yes-man".