Obsequious
Etymology
From Latin obsequium, "compliance," from obsequi, "to follow, to comply" (ob- "toward" + sequi "to follow"). It once meant simply dutiful; over centuries the sense soured into servile overeagerness.
adjective · /ub-SEE-kwee-us/
Excessively eager to please or obey; fawning.
What it names
The specific unpleasantness of flattery-as-strategy — servility that is really self-interest.
Example
The obsequious waiter hovered so attentively that dinner felt like an audition.
Related idea
Sycophantic is the near-synonym; deferential is respect without the self-abasement.