وُجُوهٌۭ يَوْمَئِذٍ خَـٰشِعَةٌ
Sentence structure
وُجُوهٌ is the nominative topic and خَـٰشِعَةٌ its predicate. يَوْمَئِذٍ is a time expression linked to the predicate.
Ayah summary
On that day, many faces will be humiliated.
وُجُوهٌۭ — Faces
Grammar: An indefinite broken-plural nominative topic.
يَوْمَئِذٍ — that Day
Grammar: A time expression in the accusative position, linked to the predicate. This phrase is linked to «وُجُوهٌ».
خَـٰشِعَةٌ — (will be) humbled
Grammar: An indefinite feminine-singular nominative active participle serving as predicate.