oblige

Etymology

From Middle English obligen, from Old French obligier, obliger, from Latin obligo, obligare, from ob- + ligo. Doublet of obligate, taken straight from Latin.

verb

1. (transitive) To constrain someone by force or by social, moral or legal means.
   I am obliged to report to the police station every week.
2. (transitive, intransitive) To do (someone) a service or favour (hence, originally, creating an obligation).
   He obliged me by not parking his car in the drive.
   The singer obliged with another song.
   In the mean time I have another trouble to give you, if you will oblige me in it; and that is to get me a sight of the famous Orrery, which I have heard you and others so often speak of; and which I think was made by Mr. Rowley, the famous Mathematical Instrument-Maker. 1719, John Harris, Astronomical dialogues between a gentleman and a lady, page 151
3. (intransitive) To be indebted to someone.
   I am obliged to you for your recent help.