The heteronym for "to comfort" is "to monitor." An upright case refers to a vertical support structure for computer components.

Hai

Yes, Slough is a heteronym, if you count names.

No, because a heteronym are words that are written identically but have different pronunciations and meanings(like homographs that are not homophones).

An example of a heteronym in a sentence would be: "The wind was strong enough to wind up the kite." In this sentence, "wind" is a heteronym because it is pronounced differently but spelled the same.