ob-¹ +

1. To require or constrain, as by law, command, conscience, or force of necessity.
2. To bind morally or legally, as by a promise or contract.
3. To place under a debt of gratitude for some benefit, favor, or service.
4. Etymology: "to bind by oath", from Old French obligier, from Latin obligare, from ob-, "to" + ligare, "to bind".

Main modern meaning "to make (someone) indebted by conferring a benefit or kindness" is from 1567; be obliged, "be bound by ties of gratitude" is from 1548. Obliging, "willing to do service or favors" is from 1632.

1. Characterized by or showing servile complaisance or deference; fawning: "He made an obsequious bow before the queen."
2. Servilely compliant or deferential: "They were obsequious servants."
3. Obedient; dutiful.

1. The branch of medical science concerned with childbirth and caring for and treating women in or in connection with childbirth.
2. Etymology: from about 1819, from obstetric, 1742; from Modern Latin obstetricus, "pertaining to a midwife"; from obstetrix (genitive of obstetricis), "midwife". Literally, "one who stands opposite (the woman giving birth)"; from obstare, "to stand opposite to".

1. The side of a coin, medal, flag, etc., that bears the principal design (opposed to reverse).
2. The front or principal surface of anything.
3. A counterpart.
4. Facing or turned toward the observer: "The obverse side of a statue."

To turn (something) so as to show a different surface.