After weeks of stress, he finally vented his pent-up rage during the meeting.

vented 是动词 vent 的过去式，vent 本意是"通风口、排气孔"，引申为"发泄、宣泄"情绪。 his 是代词 he 的所有格形式，表示"他的"。 vented his pent-up rage 意思是"发泄了他郁积的愤怒"，其中 pent-up 表示"被压抑的、郁积的"。