c.1450, "prompt to serve," from L.
obsequiosus "compliant, obedient," from
obsequium "compliance, dutiful service," from
obsequi "to accommodate oneself to the will of another," from
ob "after" +
sequi "follow" (see
sequel). Pejorative sense of "fawning, sycophantic" had emerged by 1599 (implied in
obsequiously).