What's the difference between promisor and provisor?

Promisor

Definition:

• (n.) One who engages or undertakes; a promiser.

Example Sentences:

Provisor

Definition:

• (n.) One who provides; a purveyor.
• (n.) The purveyor, steward, or treasurer of a religious house.
• (n.) One who is regularly inducted into a benefice. See Provision, 5.
• (n.) One who procures or receives a papal provision. See Provision, 6.

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