Third person singular present tense: causes embarrassment or confusion to someone; thwarts or defeats.
Present tense third person singular of discomfit, formed by adding -s to the verb stem following standard English verb conjugation.
English verbs get complicated with the -s ending — it only applies in third person present tense ('he discomfits'), which seems arbitrary until you realize this pattern evolved from Old English inflections that made much more grammatical sense centuries ago.
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